Q1.
The diagram shows an animal cell.
(a)
Name each labelled part and give its function.
A
Name ...............................................................................................................
Function ..........................................................................................................
.........................................................................................................................
B
Name ..............................................................................................................
Function .........................................................................................................
........................................................................................................................
C
Name ..............................................................................................................
Function .........................................................................................................
........................................................................................................................
(6)
(b)
(i)
This plant cell also contains chloroplasts, a cell wall and a vacuole. Label
each of these parts on the diagram.
Page 1
(3)
(ii)
Give the function of these parts of a plant cell.
Chloroplast function .........................................................................................
...........................................................................................................................
Cell wall function .............................................................................................
...........................................................................................................................
Vacuole function ..............................................................................................
...........................................................................................................................
(3)
(Total 12 marks)
Q2.
(a)
Complete the following passage
Chromosomes carry genetic information. Chromosomes are made up of
......................................... . Human body cells contain 46 chromosomes. There are
twenty-two matching pairs but the final pair does not always match. It is these two
that determine the gender, or sex, of the human. If you are a
........................................
Page 2
the final pair of chromosomes matches. If you are a ........................................
the final pair of chromosomes does not match.
(2)
(b)
Draw a labelled diagram to show that there is an equal chance of parents producing
a baby boy or girl. Use the symbols X and Y for the chromosomes.
(4)
(Total 6 marks)
Q3.
Photosynthesis takes place in green plants.
(a)
Name the substance that combines with water in photosynthesis.
.....................................................................................................................................
(1)
(b)
Where does water enter the plant?
.....................................................................................................................................
(1)
Page 3
(c)
Name two products of photosynthesis.
.....................................................................................................................................
(2)
(d)
Variegated leaves have areas that are green and areas that are white. Some
students used variegated leaves to investigate photosynthesis.
•They covered a variegated leaf with a black paper shape.
•The leaf was left in a sunny place.
•They tested the leaf for starch.
•The results were compared with a leaf that was not covered.
Area of the leaf tested
Start present after
test
covered uncovere
d
Green area
no
yes
White area
no
no
Explain why starch was present in only one of the tests.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 4
.....................................................................................................................................
(4)
(Total 8 marks)
Q4.
A person did five different activities in turn. These activities needed increasing
amounts of energy. For each activity two measurements were made. These were the rate
of contraction of the left ventricle and its stroke volume (the volume of blood pumped at
each beat). From these measurements the cardiac volume was calculated.
Some of these results are shown in the table and the bar chart.
Activity
Sitting upright
Rate of
Cardiac output
contraction
in cm3 per
of left ventricle in
minute
beats per minute
68
5 500
Slow walking
8 000
Moderate walking
98
12 000
Fast walking
130
17 500
Running
150
19 000
Page 5
(a)
(i)
Describe how a person can count the rate of beating of the left ventricle.
..........................................................................................................................
..........................................................................................................................
(1)
(ii)
Calculate the rate of ventricle contraction in beats per minute when the person
was walking slowly. Show clearly how you work out your final answer.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
Rate of ventricle contraction................................ beats per minute.
(2)
(iii)
The pattern of results for stroke volume shows an anomalous result when the
person is running. In what way is it anomalous?
..........................................................................................................................
..........................................................................................................................
(1)
(iv)
There was a change in cardiac output when the person’s movement changed
from fast walking to running. How did the heart produce this change?
..........................................................................................................................
..........................................................................................................................
(1)
(b)
Over a period of time, regular exercise can strengthen the heart muscle. This
change in the heart muscle enables a person to run for longer before lactic acid
build up occurs. Explain the reason for this.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
Page 6
(2)
(Total 7 marks)
Q5.
Regular exercise is important, as it helps to maintain an efficient supply of blood to
the muscles, the heart and the lungs. This is helped by an increase in the heart rate
during exercise.
Explain why it is necessary for the heart rate to increase during exercise.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 4 marks)
Q6.
A student‘s breathing was monitored before and after vigorous exercise. The student
breathed in and out through a special apparatus. The graphs show the changes in the
volume of air inside the apparatus. Each time the student breathed in, the line on the
graph dropped. Each time the student breathed out, the line went up.
Page 7
(a)
How many times did the student breathe in per minute:
Page 8
before exercise; ...........................................................................................................
after exercise? .............................................................................................................
(1)
(b)
On each graph, the line A – B shows how much oxygen was used. The rate of
oxygen use before exercise was 0.5 dm3per minute. Calculate the rate of oxygen
use after exercise.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Rate of oxygen use after exercise = ............................................... dm3 per minute
(2)
(c)
The breathing rate and the amount of oxygen used were still higher after exercise,
even though the student sat down to rest. Why were they still higher?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(Total 7 marks)
Q7.
The fruit fly, Drosophila, has either long wings or vestigial wings, as shown in the
diagram.
Page 9
Long-winged fly
Vestigial-winged fly
The size of the wings is determined by a pair of alleles: A and a.
Long-winged flies have one of two possible genotypes: AA or Aa.
Vestigial-winged flies have only one genotype: aa.
(a)
(i)
What is the genotype of a heterozygous fly?
...........................................................................................................................
(1)
(ii)
Why can vestigial-winged flies only have the genotype aa?
...........................................................................................................................
(1)
(b)
A male and a female long-winged fly were crossed. They produced 96 offspring.
72 of the offspring had long wings and 24 had vestigial wings.
Use a genetic diagram to explain this.
(4)
(Total 6 marks)
Page 10
Q8.
The diagram gives information about some parts of the human digestive system.
(a)
(i)
Name the organ which makes bile.
...........................................................................................................................
(1)
(ii)
Label this organ with the letter X on the diagram.
(1)
Page 11
Information in the table may help you to answer parts (b) and (c).
(b)
Name two parts of the digestive system where protein is digested.
1 .................................................................................................................................
2 .................................................................................................................................
(2)
(c)
Suggest two reasons why starch is not digested in the stomach.
1 .................................................................................................................................
.....................................................................................................................................
2 ..................................................................................................................................
.....................................................................................................................................
(2)
(Total 6 marks)
Q9.
Paula is training for a marathon. When she runs, her heart beats faster than it does
when she is resting.
Complete the sentences, using words from the box.
blood
breathe
heat
nitrogen
carbon dioxide
oxygen
glucose
respire
When she is running, Paula‘s muscle activity increases. To do this, her muscle cells
................................................. at a faster rate to give her more energy. Her muscles need
to
be supplied with ........................................... and
....................................................................
more quickly. Her heart beats faster to increase the flow
of....................................................
which carries the products ................................................................................................
and
............................................................ away from her muscles.
Page 12
(Total 6 marks)
Q10.
(a)
Alleles are different forms of the same gene.
Why does a person usually inherit two alleles of each gene?
……….………………………………………………………………………………
(1)
(b)
Some humans are albino (they have white hair and pale skin). This condition is
caused by a recessive allele, n. The other allele, N, causes a coloured pigment to
be made.
There are three possible combinations of these alleles:
NN
(i)
Nn
nn
Which one of these combinations will an albino person have?
…………………………………………………………………………………
(1)
(ii)
Two non-albino parents can sometimes have an albino child.
Which one of the following combinations of alleles must these two parents
have?
Tick ( ) the box next to the correct answer.
Tick one box only.
Parent 1
NN
NN
NN
Nn
Parent 2
Page 13
Nn
Nn
nn
nn
(1)
(Total 3 marks)
Q11.
Diagram 1 shows the nucleus of a cell at the start of meiosis.
Diagram 1
(a)
Name structure A. ......................................................................................................
(1)
(b)
During meiosis, the nucleus shown in diagram 1 will divide twice to form four nuclei.
Complete diagram 2 to show the appearance of one of these nuclei.
Page 14
Diagram 2
(2)
(Total 3 marks)
Q12.
(a)
(i)
What name is given to an enzyme which catalyses the breakdown of
protein?
...........................................................................................................................
(1)
(ii)
What product is formed when protein is broken down by the enzyme?
...........................................................................................................................
(1)
The table shows the effect of pH on the activity of an enzyme which catalyses the
breakdown of protein.
pH
1.0
2.0
3.0
4.0
5.0
Rate of formation of product in mmol
per minute
10.5
23.0
10.5
2.5
0.0
(b)
Draw a graph of the data in the table.
Page 15
(3)
(c)
The enzyme is produced by the human digestive system.
(i)
At what pH does this enzyme work best? ........................................................
(1)
(ii)
Suggest which part of the digestive system produces this enzyme.
...........................................................................................................................
(1)
(d)
Why is it necessary to break down proteins in the digestive system?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 16
(3)
(Total 10 marks)
Q13.
The diagram shows an animal cell.
(a)
(i)
Name structures A and B by choosing the correct words from the box.
cell membrane
cell wall
cytoplasm
nucleus
vacuole
Structure A .......................................................................................................
Structure B .......................................................................................................
(2)
(ii)
Which structure named in the box controls the passage of substances in and
out of the cell?
...........................................................................................................................
(1)
Page 17
(b)
Distance P to Q on the diagram is the diameter of the cell. This distance was
measured on three cells using a microscope. The results were as follows:
cell 1: 63 micrometres
cell 2: 78 micrometres
cell 3: 69 micrometres
Calculate the average diameter of these cells. Show clearly how you work out your
final answer.
.....................................................................................................................................
.....................................................................................................................................
Average diameter = ................................... micrometres
(2)
(Total 5 marks)
Q14.
The diagram shows the apparatus used to investigate the digestion of milk fat by an
enzyme. The reaction mixture contained milk, sodium carbonate solution (an alkali) and
the enzyme. In Experiment 1, bile was also added. In Experiment 2, an equal volume of
water replaced the bile. In each experiment, the pH was recorded at 2-minute intervals.
Either: Experiment 1
or:
milk (contains fat)
sodium carbonate solution
bile
enzyme
Page 18
Experiment 2
milk (contains fat)
sodium carbonate solution
water
enzyme
The results of the two experiments are given in the table.
(a)
Milk fat is a type of lipid. Give the name of an enzyme which catalyses the
breakdown of lipids.
.............................................................................................................................
......
(1)
(b)
What was produced in each experiment to cause the fall in pH?
.............................................................................................................................
......
(1)
(c)
(i)
For Experiment 1, calculate the average rate of fall in pH per minute, between
4 minutes and 8 minutes. Show clearly how you work out your final answer.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
............................................. pH units per minute
(2)
(ii)
Why was the fall in pH faster when bile was present?
Page 19
...........................................................................................................................
...........................................................................................................................
(1)
(Total 5 marks)
Q15.
The diagram shows two patterns of cell division. Cell division type A is used in
gamete formation. Cell division type B is used in normal growth.
(a)
Name the two types of cell division, A and B, shown in the diagram.
Type A ........................................................................................................................
Type B ........................................................................................................................
(2)
(b)
Name the process in which an egg and sperm join together.
Page 20
.............................................................................................................................
........
(1)
(c)
Cell 1 contains 46 chromosomes. How many chromosomes will there be in:
(i)
cell 10; ..............................................................................................................
(1)
(ii)
cell 14?
.............................................................................................................
(1)
(Total 5 marks)
Q16.
(a)
The equation describes the process of photosynthesis.
carbon dioxide + .................. + light energy
(i)
glucose + ..................
Write in the names of the two missing substances.
(2)
(ii)
Name the green substance which absorbs the light energy.
...........................................................................................................................
(1)
(b)
(i)
In bright sunlight, the concentration of carbon dioxide in the air can limit the
rate of photosynthesis. Explain what this means.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
Page 21
(ii)
Give one environmental factor, other than light intensity and carbon dioxide
concentration, which can limit the rate of photosynthesis.
...........................................................................................................................
(1)
(Total 6 marks)
Q17.
Bread contains starch, protein and fat.
(a)
Complete each sentence by choosing the correct words from the box.
amino acids
protein
fat
starch
fatty acids
sugar
Amylase speeds up the digestion of .................................... . The product of this
digestion
is ............................. . Protease speeds up the digestion of ............................. .
The product of this digestion is .............................................. .
(4)
(b)
Why do molecules of starch, protein and fat need to be digested?
.............................................................................................................................
........
.............................................................................................................................
........
(2)
(c)
In which part of the digestive system does the digestion of starch begin?
Draw a ring around your answer.
Page 22
large intestine
mouth
small intestine
stomach
(1)
(d)
What do we call substances like amylase and protease which speed up chemical
reactions?
.............................................................................................................................
........
(1)
(Total 8 marks)
Q18.
Complete each sentence by choosing the correct terms from the box.
23
dominant
46
female
ADH
male
DNA
recessive
XX
XY
strong
YY
weak
A gene is made up of a substance called ............................. . Genes are found on
chromosomes
and most human cells contain ................................. pairs of chromosomes. In females the
two
sex chromosomes are ........................, but in males the two sex chromosomes are
.................. .
Alleles are alternative forms of a gene. Two healthy parents can sometimes have a child
with a
genetic disorder such as cystic fibrosis. This is because cystic fibrosis is caused by a
..................................... allele. The two parents are healthy because they also have the
..................................... allele.
(Total 6 marks)
Page 23
##
Read the article from a recent newspaper.
‘King Kong’ with inch-wide teeth who
walked alongside early man.
Gigantopithecus blackii, R F Zallinger
The largest ape that walked on Earth was a prehistoric animal that weighed up to 540 kg. It was 3
metres tall and had inch-wide teeth. This giant ape roamed bamboo forests until 100 000 years ago.
It is quite likely that the giant ape lived at the same time as early humans.
(a)
What evidence might scientists have that the great ape existed?
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
The drawing is an artist’s impression of what the giant ape might have looked like.
Why do scientists not know exactly what the animal looked like?
.....................................................................................................................................
.....................................................................................................................................
(1)
Page 24
(c)
Scientists do not know why this giant ape became extinct.
Suggest two reasons why this giant ape became extinct.
1 ..................................................................................................................................
.....................................................................................................................................
2 ..................................................................................................................................
.....................................................................................................................................
(2)
(Total 4 marks)
Q20.
Red squirrels live in trees. They eat seeds from the cones of conifer trees. Squirrels
store cones in ‘larders’ on the ground. These larders provide food through the winter.
Each red squirrel makes and defends one larder.
Scientists monitor squirrel numbers to find the best habitats for the squirrel’s survival. In
one investigation, scientists estimated the numbers of squirrels in different types of
woodland. Each woodland contains a different species of conifer tree.
Here is their method.
•
Ten woods of each type of woodland were surveyed.
•
In each wood scientists measured out two transects (strips), each 600 m long and
10 m wide.
•
A scientist walked slowly down the centre of each transect, recording the number of
squirrel larders he could see.
Page 25
(a)
(i)
How many transects all together did the scientists survey in each type of
woodland?
Number of transects ..................................................
(1)
(ii)
What was the total area surveyed in one wood?
...........................................................................................................................
Area .................................................................... m2
(1)
(b)
Name one variable that was controlled in this investigation.
.....................................................................................................................................
(1)
(c)
(i)
The scientists recorded the number of larders instead of the number of
squirrels they saw.
Explain how this could have increased the accuracy of the investigation.
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
This method of counting the number of larders could have led to an inaccurate
estimate of the number of squirrels.
Explain how.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(d)
The results of the investigation are shown in the graph.
Page 26
The horizontal mark on each bar represents the mean number of larders per
hectare of woodland.
The range of the number of larders observed for Douglas fir woodland was 0 to 1.9
per hectare.
(i)
What was the range of the number of larders per hectare in the Spruce fir
woodland?
...........................................................................................................................
(1)
(ii)
The highest mean number of larders per hectare was found in Blue spruce
woodland.
Suggest one explanation for this.
...........................................................................................................................
...........................................................................................................................
(1)
(Total 8 marks)
Page 27
Q21.
The table shows the amounts of energy used in running and in walking at different
speeds by people of different body masses.
Energy used in kilojoules per hour
Activity
34 kg
person
50 kg
person
70 kg
person
90 kg
person
Running, 9 km per hour
1530
1850
2770
3700
Running, 11 km per hour
2140
2560
3860
5120
Running, 16 km per hour
2980
3570
5380
7140
Walking, 3 km per hour
530
670
1010
1340
Walking, 5 km per hour
740
880
1340
1760
Walking, 7 km per hour
1030
1240
1850
2480
(a)
Describe two patterns you can see in the data.
1 .................................................................................................................................
....................................................................................................................................
2 .................................................................................................................................
....................................................................................................................................
(2)
(b)
Our breathing rate is much higher when running than when walking.
Explain the advantage of this to the body.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(3)
(Total 5 marks)
Page 28
Q22.
The diagram shows a yeast cell.
Label structures A and B on the diagram.
Choose your answers from the list in the box.
cell membrane
cell wall
nucleus
vacuole
(Total 2 marks)
Q23.
Changing the conditions in which plants grow affects how fast they grow.
The diagram shows a propagator in which scientists can control temperature, light
intensity and carbon dioxide concentration.
Page 29
The graph shows the effects of changing the temperature, light intensity and carbon
dioxide concentration on the growth of lettuce plants.
(a)
Describe and explain the effect of increasing light intensity on the mean mass of
lettuce plants at 4% carbon dioxide and 15 °C.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
Page 30
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(3)
(b)
Growers wish to make maximum profits from their lettuces.
What do they need to consider before making decisions about the growing
conditions for their lettuces?
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(c)
The nutrient solution contains nitrate ions and magnesium ions.
Complete the table to show the functions of these ions in plants and their deficiency
symptoms.
Ion
Nitrat
e
Magn
esium
Function in plants
Deficiency symptoms
.........................................................
........................................................
.........................................................
........................................................
.........................................................
.........................................................
.........................................................
..........................................................
.........................................................
.........................................................
.........................................................
.........................................................
(4)
(Total 9 marks)
Page 31
Q24.
Chromosomes contain molecules of DNA. Genes are small sections of DNA.
(a)
Each gene contains a code.
What does a cell use this code for?
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(b)
DNA fingerprints can be used to identify people. One example of the use of DNA
fingerprints is to find out which man is the father of a child.
The diagram shows the DNA fingerprints of a child, the child’s mother and two men
who claim to be the child’s father.
The numbers refer to the bars on the DNA fingerprints.
(i)
Which man, A or B, is more likely to be the father of the child?
Use the numbers on the DNA fingerprints to explain your choice.
In your answer you should refer to all four people.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
Page 32
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(3)
(ii)
Only half the bars of the child’s DNA fingerprint match the mother’s DNA
fingerprint.
Explain why.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(Total 7 marks)
Q25.
Cystic fibrosis is an inherited disorder that can seriously affect health.
(a)
Which one of these is affected by cystic fibrosis?
Draw a ring around your answer.
blood
cell membranes
kidneys
nervous system
(1)
(b)
The diagram shows the inheritance of cystic fibrosis in a family. The allele that
produces cystic fibrosis is recessive.
Page 33
(i)
Explain why Alice inherited cystic fibrosis.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(ii)
Explain why Ted did not inherit cystic fibrosis.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(c)
Bob and Carol know that there is a risk that their next baby will have cystic fibrosis.
Embryos can be screened for the allele that produces cystic fibrosis.
Page 34
Many people support the screening of embryos, but others do not.
(i)
Suggest one reason why many people support the screening of embryos for
the cystic fibrosis allele.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(1)
(ii)
Suggest one reason why many people are against the screening of embryos
for the cystic fibrosis allele.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(1)
(Total 7 marks)
Q26.
Enzymes are used in biological detergents.
(a)
Name the type of enzyme that digests stains containing fats.
....................................................................................................................................
(1)
(b)
A new detergent is marketed as being ‘environmentally-friendly’.
Scientists compared the performance of this new detergent with an existing
detergent.
They measured the time taken by the two detergents to remove a fat stain at
different temperatures.
The graph shows their results.
Page 35
(i)
Describe the effect of increasing the temperature on the time taken by the
existing detergent to remove the stain.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(ii)
The new detergent works at a lower temperature than the existing one.
Is the new detergent likely to be more ‘environmentally-friendly’ than the
existing detergent?
Draw a ring around your answer.
Yes / No
Explain the reason for your answer.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(c)
Neither detergent works well at 60 °C.
Explain why.
Page 36
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(Total 7 marks)
Q27.
Green plants are able to make their own food.
Complete each sentence by drawing a ring around the correct answer in the box.
diffusion
(a)
Green plants make their own food during the process of
photosynthesis
respiration
(1)
(b)
This process can be summarised by the equation:
mineral salts
carbon dioxide + water → glucose +
light
oxygen
(1)
chlorophyll
(c)
The energy needed for this process is trapped for the plant by
glucose
light
Page 37
(1)
chlorophyll
(d)
Some of the food made by plants is stored as insoluble
glucose
starch
(1)
(Total 4 marks)
Q28.
The diagram shows a cell from the lining of the lung. This cell is specialised to allow
gases to pass through quickly.
(a)
Use words from the box to label structures A, B and C.
cell membrane
chloroplast
cytoplasm
mitochondria
nucleus
(3)
(b)
(i)
Which feature of this cell allows oxygen to pass through quickly?
Put a tick ( ) in the box next to your choice.
It is thin.
Page 38
It has a large nucleus.
It has many mitochondria.
(1)
(ii)
Complete the sentence by drawing a ring around the correct answer in the
box.
diffusion
Oxygen passes through this cell by
osmosis
respiration
(1)
(Total 5 marks)
Q29.
A student pedalled an exercise cycle at constant speed for 5 minutes. The student’s
heart rate was recorded at one-minute intervals during the exercise and also during
recovery.
The results are shown in the graph.
Page 39
(a)
Describe, in as much detail as you can, the changes in heart rate between 0 and 14
minutes.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(b)
How do arteries supplying the leg muscles alter the rate of blood flow through them
during exercise?
.....................................................................................................................................
.....................................................................................................................................
(1)
(c)
Explain how an increase in heart rate helped the student during exercise.
.....................................................................................................................................
.....................................................................................................................................
Page 40
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(Total 8 marks)
Q30.
Bile is produced in the liver, stored in the gall bladder, then released into the small
intestine.
(a)
Explain how bile affects the digestion of food in the small intestine.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(b)
Bile contains bile pigments and cholesterol.
If the diet contains too much cholesterol, some of it may form ‘gallstones’ in the bile.
These gallstones may prevent bile from moving out of the gall bladder into the
small intestine.
Bilirubin is a yellow-brown bile pigment. This pigment is produced by the liver from
haemoglobin released by broken-down red blood cells.
Suggest how gallstones may produce the following symptoms:
(i)
very pale faeces
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
Page 41
...........................................................................................................................
(2)
(ii)
jaundice (a yellow tinge to the skin).
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 6 marks)
Q31.
In the 1850s, Gregor Mendel carried out breeding experiments using peas.
(a)
The importance of Mendel’s work was not recognised until the early 1900s.
Explain why.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(b)
A student repeated one of Mendel’s experiments.
The flow chart shows her procedure.
Page 42
The diagram shows a representative sample of seeds produced by second
generation plants.
(i)
Describe how the student could obtain a sample that is representative of
seeds produced by the second generation.
...........................................................................................................................
...........................................................................................................................
(1)
Page 43
(ii)
What was the approximate ratio of yellow seeds to green seeds in the seeds
produced by the second generation?
...........................................................................................................................
(1)
(iii)
Seed colour in peas is controlled by a single gene which has two alleles.
Use a genetic diagram to show why this ratio of yellow seeds to green seeds was
produced by the second generation.
Use the symbol A to represent the dominant allele, and a to represent the recessive
allele.
(4)
(Total 8 marks)
Q32.
The diagram shows an industrial process. Containers X and Y contain enzymes.
(a)
Starch syrup slowly trickles into container X.
Page 44
The enzymes in container X convert the starch into glucose (sugar).
The enzymes in container Y convert the glucose into fructose.
The equation shows what happens in containers X and Y.
Enzyme A
starch
Enzyme B
glucose
fructose
Choose words from the box to name enzyme A and enzyme B.
carbohydrase
isomerase
lipase
protease
Enzyme A ................................................
Enzyme B ................................................
(2)
(b)
Fructose syrup is much sweeter than glucose syrup.
Why do manufacturers of slimming foods use fructose syrup rather than glucose
syrup?
.....................................................................................................................................
.....................................................................................................................................
(1)
(c)
Here are some of the properties of enzymes:
•
they all work at atmospheric pressures
•
they are easily broken down by high temperature or the wrong pH
•
they are soluble in water, so it may be difficult to separate them from products
•
they are expensive to buy
•
they work well at 25 – 45 °C.
Use only the information above to answer these questions.
(i)
Give two advantages of using enzymes in industry.
1 .......................................................................................................................
Page 45
2 .......................................................................................................................
(2)
(ii)
Give two disadvantages of using enzymes in industry.
1 .......................................................................................................................
2 .......................................................................................................................
(2)
(Total 7 marks)
Q33.
The diagram shows bushes in a hedge growing near to a house.
The bushes were the same species and the same age.
(a)
(i)
The student said, “I have noticed that the short bushes grow next to the
house. I think that the more light the bushes get, the faster they will grow.”
Draw lines to match each of the student’s statements to the correct term.
Draw only two lines.
Page 46
(2)
(ii)
Complete the word equation for photosynthesis.
..................................... +water (+ light energy)  ................................ +
oxygen
(2)
(b)
The student decided to investigate the effect of light intensity on the rate of
photosynthesis.
She used the apparatus shown in the diagram.
She measured the rate of photosynthesis by counting the number of gas bubbles
given off each minute.
(i)
Suggest how the student varied the intensity of the light received by the
pondweed.
...........................................................................................................................
Page 47
...........................................................................................................................
(1)
(ii)
The student’s results are shown on the graph.
Describe the pattern shown on the graph.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(iii)
This is what the student wrote for her conclusion.
“Increasing the light intensity increases the rate of photosynthesis of the
pondweed.”
Why was her conclusion incomplete?
...........................................................................................................................
...........................................................................................................................
(1)
(Total 8 marks)
Page 48
Q34.
The diagram shows a spider plant during one type of reproduction.
Complete the sentences using words from the box.
asexual
characteristics
gametes
(a)
chromosomes
genes
mitosis
sexual
The colour and shape of the leaves of a spider plant are known
as ................................................................................................................................
(1)
(b)
The shape of the leaves is controlled by ....................................................................
(1)
(c)
The thread-like structures inside the nucleus of the cells are
called ..........................................................................................................................
(1)
(d)
The spider plant produces new cells in the runner by a process
called ..........................................................................................................................
(1)
Page 49
(e)
This type of reproduction is called ...................................................... reproduction.
(1)
(Total 5 marks)
Q35.
The diagram shows a group of muscle cells from the wall of the intestine.
(a)
On the diagram, use words from the box to name the structures labelled A, B and
C.
cell membrane
cell wall
chloroplast
cytoplasm
nucleus
(3)
(b)
How are these muscle cells adapted to release a lot of energy?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 5 marks)
Page 50
Q36.
The dodo is an extinct bird. The drawing shows an artist’s impression of the bird.
The dodo lived on a small island in the middle of the Indian Ocean. Its ancestors were
pigeon-like birds which flew to the island millions of years ago. There were no predators
on the island. There was a lot of fruit on the ground. This fruit became the main diet of the
birds. Gradually, the birds became much heavier, lost their ability to fly and evolved into
the dodo.
(a)
Suggest an explanation for the evolution of the pigeon-like ancestor into the
flightless dodo.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
Page 51
(b)
The dodo became extinct about 80 years after Dutch sailors first discovered the
island in the eighteenth century.
Scientists are uncertain about the reasons for the dodo’s extinction.
Suggest an explanation for this uncertainty.
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 5 marks)
Q37.
A manufacturer is trying to improve the quality of the biological detergent he
produces.
Scientists at his company carried out the following experiments on enzymes:
•
•
•
•
•
•
Samples of lipase were collected from five different types of bacterium, A, B, C, D
and E.
The samples were diluted to give the same concentration of lipase.
Agar jelly containing a lipid was prepared in a dish. This forms a cloudy mixture
which becomes clear when the lipid is digested.
Five small holes were cut into the agar.
Two drops of lipase solution from bacterium A was added to hole A.
This process was repeated for each sample of lipase.
Diagram 1 shows the appearance of the dish.
Diagram 1
Page 52
Diagram 2 shows the appearance of the dish 24 hours later.
Diagram 2
(a)
(i)
Which type of bacterium, A, B, C, D or E, produced the most effective lipase
in this investigation?
Write your answer, A, B, C, D or E, in the box.
(1)
(ii)
Explain your answer.
...........................................................................................................................
...........................................................................................................................
(1)
Page 53
(b)
The manufacturer plans to add the most effective lipase to the washing powders he
produces.
Suggest two other factors he should investigate before deciding which lipase is the
most effective.
1 ..................................................................................................................................
.....................................................................................................................................
2 ..................................................................................................................................
.....................................................................................................................................
(2)
(c)
Many biological detergents cannot be used at high temperatures.
Explain why.
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 5 marks)
Q38.
(a)
(i)
Complete the word equation for photosynthesis.
carbon dioxide + ........................ (+ light energy) → glucose + ........................
(2)
(ii)
Most of the carbon dioxide that a plant uses during photosynthesis is
absorbed from the air.
Give one other source of carbon dioxide for a plant.
Draw a ring around your answer.
the soil
respiration in the plant
osmosis in the plant
water
(1)
A student investigated the conditions that plants need for photosynthesis.
Page 54
The leaves of the plant he used had green and white parts.
Diagram 1 shows how part of one leaf was covered in black (opaque) card.
The plant was placed in a warm, sunny area and was watered well.
Eight hours later the leaf was removed from the plant and was tested for starch.
The results of the test are shown in Diagram 2, the shaded parts show where starch was
present.
Diagram 1
(b)
Diagram 2
Name the two independent variables in this investigation.
1 ..................................................................................................................................
.....................................................................................................................................
2 ..................................................................................................................................
.....................................................................................................................................
(2)
(c)
Why was no starch found in:
(i)
the part of the leaf labelled A
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
the part of the leaf labelled B?
...........................................................................................................................
...........................................................................................................................
(1)
(Total 7 marks)
Page 55
Q39.
Diagram 1 shows the nucleus of a body cell as it begins to divide by mitosis.
Diagram 1
(a)
Use a word from the box to label Diagram 1.
alleles
chromosomes
gametes
(1)
(b)
Complete Diagram 2 to show what the nucleus of one of the cells produced by this
mitosis would look like.
Diagram 2
(1)
Page 56
(c)
Stem cells from a recently dead embryo can be grown in special solutions.
Some facts about stem cells are given below.
•
Stem cells from an embryo can grow into any type of tissue.
•
Stem cells may grow out of control, to form cancers.
•
Large numbers of stem cells can be grown in the laboratory.
•
Stem cells may be used in medical research or to treat some human diseases.
•
Patients treated with stem cells need to take drugs for the rest of their life to
prevent rejection.
•
Collecting and growing stem cells is expensive.
Use only the information above to answer these questions.
(i)
Give two advantages of using stem cells.
1 ........................................................................................................................
...........................................................................................................................
2 ........................................................................................................................
...........................................................................................................................
(2)
(ii)
Give two disadvantages of using stem cells.
1 ........................................................................................................................
...........................................................................................................................
2 ........................................................................................................................
...........................................................................................................................
(2)
(Total 6 marks)
Q40.
(a)
The diagrams show cells containing and surrounded by oxygen molecules.
Page 57
Oxygen can move into cells or out of cells.
Into which cell, A, B, C or D, will oxygen move the fastest?
Write your answer, A, B, C or D, in the box.
(1)
(b)
Draw a ring around the correct word to complete each sentence.
diffusion
(i)
Oxygen is taken into cells by the process of
osmosis
.
respiration
(1)
breathing
(ii)
Cells need oxygen for
photosynthesis
respiration
Page 58
.
(1)
membranes
(iii)
The parts of cells that use up the most oxygen are the
mitochondria
.
nuclei
(1)
diffusion
(iv)
Some cells produce oxygen in the process of
photosynthesis
.
respiration
(1)
(Total 5 marks)
Q41.
Diagram 1 shows a cell from a leaf.
Diagram 1
(a)
How is the leaf cell specialised to carry out photosynthesis?
Tick ( ) one box.
Page 59
It has a permanent vacuole.
It has many chloroplasts.
It has cytoplasm.
It has many mitochondria.
(1)
(b)
Diagram 2 shows another type of plant cell.
Diagram 2
Give two ways in which this cell is different from an animal cell.
1 ..................................................................................................................................
.....................................................................................................................................
2 ..................................................................................................................................
.....................................................................................................................................
(2)
(Total 3 marks)
##
(a)
The table shows the effect of exercise on the action of one person’s heart.
Page 60
At rest
During
exercise
Heart rate in beats per minute
72
165
Volume of blood leaving the heart in each
beat
in cm3
75
120
Heart output in cm3 per minute
(i)
5400
Calculate the heart output for this person during exercise.
Show clearly how you work out your answer.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
Answer = .............................. cm3 per minute
(2)
(ii)
During exercise, more oxygen is carried to the working muscles.
Explain why this is helpful during exercise.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(b)
Give two other changes in the body that help to increase the amount of oxygen
delivered to the working muscles during exercise.
1 ..................................................................................................................................
.....................................................................................................................................
2 ..................................................................................................................................
.....................................................................................................................................
Page 61
(2)
(Total 6 marks)
Q43.
The diagram shows a family tree in which some individuals have an inherited
disorder, which may cause serious long-term health problems.
(a)
What proportion of the children of A and B have the disorder?
.....................................................................................................................................
(1)
(b)
Explain the evidence from the diagram which shows that the allele for the disorder
is dominant.
Use the appropriate letters to identify individuals in your answer.
You may use genetic diagrams in your explanation. There is space for you to draw
a genetic diagram at the top of the facing page.
.....................................................................................................................................
Page 62
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(c)
(i)
What is meant by ‘embryo screening’?
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
A doctor suggests that couple C and D should have their embryos screened
but that couple G and H do not need this procedure.
Explain the reasons for the doctor’s suggestions.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(Total 8 marks)
Q44.
A manufacturer of slimming foods is investigating the effectiveness of
carbohydrases from different microorganisms.
Page 63
Iodine solution is a pale golden brown, transparent solution. Starch reacts with iodine to
form a dark blue mixture.
Known concentrations of starch are added to iodine solution. The mixture is placed in a
colorimeter which measures the percentage of light passing through the mixture.
Graph 1 shows the results.
(a)
Explain why less light passes through the mixture when the starch is more
concentrated.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
The manufacturer adds carbohydrase from each of three different microorganisms,
A, B and C, to starch in flasks at 40 °C.
Every minute a sample of the mixture is added to iodine solution and placed in the
colorimeter.
Graph 2 shows these results.
Page 64
(i)
When the concentration of starch reaches 2 %, digestion is considered to be
sufficient for the next stage in the manufacture of the slimming food.
How long does this take for the most effective carbohydrase?
Show clearly how you work out your answer.
...........................................................................................................................
...........................................................................................................................
.............................. minutes
(2)
(ii)
Explain why the manufacturer carried out the investigation at 40 °C.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
Page 65
(c)
Carbohydrases convert starch into glucose. To complete the manufacture of the
slimming food the glucose should be converted into fructose.
(i)
Name the enzyme which would be used to convert glucose into fructose.
...........................................................................................................................
(1)
(ii)
Explain why fructose, rather than glucose, is used in slimming foods.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 8 marks)
Q45.
A gardener grows tomatoes.
He wants to find out how to get the biggest mass of tomatoes.
He plants different varieties of tomato against different walls in his garden.
Use these results to answer the questions.
Page 66
(a)
The gardener wants his test to be fair.
Name one condition which he should keep the same for all his tomato plants.
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
The table shows the gardener’s results.
Variety of tomato plant
Wall they were planted against
Mean mass of tomatoes produced
in kilograms per plant
(i)
Sungold Sungold Sungold Sungold Nugget Champion
North
West
South
East
East
East
3.5
3.0
1.2
2.5
3.2
2.7
To obtain the biggest mass of tomatoes, against which wall is it best to grow
the tomato plants?
Tick ( ) one box.
North wall
South wall
East wall
West wall
(1)
(ii)
To obtain the biggest mass of tomatoes, which variety of tomato plant would it
be best to grow?
...........................................................................................................................
(1)
Page 67
(c)
From the information in the table, the gardener’s test was not fair.
Give one way in which the test was not fair.
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 4 marks)
Q46.
A woman gives birth to triplets.
Two of the triplets are boys and the third is a girl.
The triplets developed from two egg cells released from the ovary at the same time.
The diagram shows how triplets A, B and C developed.
(a)
Which stages on the diagram show gametes?
Page 68
Draw a ring around your answer.
1 and 2
2 and 3
3 and 7
1 and 7
(1)
(b)
Embryo B is male.
Which of the following explains why embryo B is male?
Tick ( ) one box.
Cell P has an X chromosome; cell R has an X chromosome.
Cell P has a Y chromosome; cell R has an X chromosome.
Cell P has an X chromosome; cell R has a Y chromosome.
(1)
(c)
The children that develop from embryos A and C will not be identical.
Explain why.
You may use words from the box in your answer.
egg
genes
sperm
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(d)
Single cells from an embryo at Stage 7 can be separated and grown in a special
solution.
(i)
What term describes cells that are grown in this way?
Draw a ring around your answer.
lleles
screened cells
Page 69
stem cells
(1)
(ii)
What happens when the cells are placed in the special solution?
Tick ( ) two boxes.
The cells divide
The cells fertilise
The cells differentiate
The cells separate
(2)
(iii)
Give one use of cells grown in this way.
...........................................................................................................................
...........................................................................................................................
(1)
(iv)
Some people might object to using cells from embryos in this way.
Give one reason why.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(1)
(Total 9 marks)
Q47.
Enzymes have many uses in the home and in industry.
(a)
Which type of organism is used to produce these enzymes?
Tick ( ) one box.
Page 70
Mammals
Microorganisms
Plants
(1)
(b)
Babies may have difficulty digesting proteins in their food. Baby food manufacturers
use enzymes to ‘pre-digest’ the protein in baby food to overcome this difficulty.
Use words from the box to complete the sentences.
amino acids
(i)
amylases
proteases
sugars
Proteins are ‘pre-digested’ using enzymes called
................................................... .
(1)
(ii)
This pre-digestion produces
.................................................................................... .
(1)
(c)
A baby food manufacturer uses enzyme V to pre-digest protein.
He tries four new enzymes, W, X, Y and Z, to see if he can reduce the time taken to
pre-digest the protein.
The graph shows the time taken for the enzymes to completely pre-digest the
protein.
The manufacturer uses the same concentration of enzyme and the same mass of
protein in each experiment.
Page 71
(i)
How long did it take enzyme V to pre-digest the protein?
minutes
(1)
(ii)
Which enzyme would you advise the baby food manufacturer to use?
Draw a ring around your answer.
enzyme V
enzyme W
enzyme X
enzyme Y
enzyme Z
Give a reason for your answer.
...........................................................................................................................
...........................................................................................................................
(2)
(iii)
Give two factors which should be controlled in the baby food manufacturer’s
investigations.
Tick ( ) two boxes.
Oxygen concentration
Page 72
Temperature
Light intensity
pH
(2)
(Total 8 marks)
Q48.
This question is about cells.
(a)
(i)
The diagram shows a sperm cell.
Use words from the box to label parts A and B.
cell membrane
cytoplasm
nucleus
(2)
(ii)
The diagram shows a cell from a leaf.
Page 73
Give the letters of two parts of the leaf cell which would not be found in a
sperm cell.
and
.
(1)
(b)
Sperm cells have many mitochondria.
Why do sperm cells need many mitochondria?
Tick ( ) one box.
Sperm cells are involved in fertilisation.
Sperm cells are produced in very large numbers.
Sperm cells need a lot of energy to swim.
(1)
(Total 4 marks)
Q49.
There is a large amount of evidence that evolution is taking place.
(a)
Scientists are uncertain about how life started on Earth.
Explain why.
........................................................................................................................
Page 74
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(b)
Salamanders are terrestrial amphibians.
The diagram shows the distribution of four different species of salamander in a
country.
Originally, there was only one species of salamander in the country.
Suggest an explanation for the development of the four different species.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(5)
(Total 7 marks)
Page 75
Q50.
The diagram shows the apparatus used to investigate the digestion of milk fat by an
enzyme. The reaction mixture contained milk and the enzyme.
In Experiment 1, bile was also added.
In Experiment 2, an equal volume of water replaced the bile.
In each experiment, the pH was recorded at 2 minute intervals.
The results of the two experiments are given in the table.
pH
Time in minutes
Experiment 1: with bile
Experiment 2: without
bile
0
9.0
9.0
2
8.8
9.0
4
8.7
9.0
6
8.1
8.8
Page 76
(a)
8
7.7
8.6
10
7.6
8.2
Milk fat is a type of lipid.
Explain why the pH changed in experiment 2.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(b)
(i)
For Experiment 1, calculate the average rate of fall in pH per minute,
between 4 minutes and 8 minutes.
Show clearly how you work out your final answer.
...............................................................................................................
...............................................................................................................
................................. pH units per minute
(2)
(ii)
The average rate of fall in pH per minute for Experiment 2 was 0.1 units of pH
per minute.
Explain the difference in the rate of fall in pH when bile is present.
...............................................................................................................
...............................................................................................................
(1)
(Total 5 marks)
Q51.
DNA fingerprinting can be used to identify people. One example of the use of DNA
Page 77
fingerprinting is to find out which man is the father of a child.
The diagram shows the DNA fingerprints of a child, the child’s mother and two men who
claim to be the child’s father.
The numbers refer to the bars on the DNA fingerprints.
(a)
Only half the bars of the child’s DNA fingerprint match the mother’s DNA fingerprint.
Explain why.
........................................................................................................................
........................................................................................................................
(2)
(b)
Which man, A or B, is more likely to be the father of the child?
Use the numbers on the DNA fingerprints to explain your choice.
In your answer you should refer to all four people.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(3)
(Total 5 marks)
Page 78
Q52.
Sometimes babies are born with extra fingers or toes as shown in the photograph.
This condition is called polydactyly.
©CNRI / SCIENCE PHOTO LIBRARY
The diagram shows the inheritance of polydactyly in a family.
(a)
Polydactyly is caused by a dominant allele, D.
The recessive allele of the gene is represented by d.
Use one genetic diagram to show the inheritance of the polydactyly gene by R and
S.
Page 79
(4)
(b)
In this question you will be assessed on using good English, organising information
clearly and using specialist terms where appropriate.
Embryos can be screened for genetic disorders.
Many people would favour the use of embryo screening for cystic fibrosis but not for
polydactyly.
Compare the issues involved in the use of embryo screening for cystic fibrosis and
for polydactyly.
You should use your knowledge and understanding of the process and the two
conditions.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(6)
(Total 10 marks)
Page 80
Q53.
The diagram shows one way that stem cells can be produced from human embryos.
Sue Medaris/University of Wisconsin-Madison
(a)
Stem cells can be used to treat a condition such as paralysis.
Explain why.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(b)
During pregnancy, an umbilical cord and a placenta join the embryo to the mother.
At birth the umbilical cord is cut.
Stem cells can be obtained from the umbilical cord.
Many people think that the stem cells for treating human conditions should be
obtained from umbilical cords rather than human embryos.
Suggest one reason why.
........................................................................................................................
........................................................................................................................
(1)
Page 81
(c)
Stem cells divide by mitosis. Gametes are formed by meiosis.
Give two differences between mitosis and meiosis.
1 .....................................................................................................................
........................................................................................................................
2 .....................................................................................................................
........................................................................................................................
(2)
(Total 5 marks)
Q54.
Red squirrels live in trees. They eat seeds from the cones of conifer trees. Squirrels
store cones in ‘larders’ on the ground. These larders provide food through the winter.
Each red squirrel makes and defends one larder.
Scientists monitor squirrel numbers to find the best habitats for the squirrel’s survival. In
one investigation, scientists estimated the numbers of squirrels in different types of
woodland. Each woodland contains a different species of conifer tree.
Here is their method.
•
Ten woods of each type of woodland were surveyed.
•
In each wood scientists measured out two transects (strips), each 600 m long and
10 m wide.
•
A scientist walked slowly down the centre of each transect, recording the number of
squirrel larders he could see.
Page 82
(a)
Name one variable that was controlled in this investigation.
........................................................................................................................
(1)
(b)
(i)
The scientists recorded the number of larders instead of the number of
squirrels they saw.
How could this have increased the accuracy of the investigation?
...............................................................................................................
...............................................................................................................
(1)
(ii)
This method of counting the number of larders could have led to an inaccurate
estimate of the number of squirrels.
Explain how.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(c)
The results of the investigation are shown on the graph.
Page 83
Each bar represents the range of the number of larders in each type of woodland.
The horizontal mark on each bar represents the mean number of larders per hectare
of woodland.
(c)
A student concluded ‘You will always find more squirrels in spruce woodland than in
fir woodland.’
Is the student’s conclusion justified by the data in the graph?
Explain the reasons for your answer.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(Total 6 marks)
Page 84
Q55.
The diagram shows a bacterium.
On the drawing, name the structures labelled A, B, C and D.
(Total 4 marks)
Q56.
Plants produce food by photosynthesis.
(a)
Complete the equation for photosynthesis.
carbon dioxide + .......................... (+ light energy) → glucose + ..........................
(2)
Some students investigated the effect of temperature on the rate of photosynthesis in
pond weed. They set up the apparatus and altered the temperature using ice and hot
water. They counted the number of bubbles given off in a minute at different
temperatures.
Page 85
(b)
Why did the students use a water bath?
........................................................................................................................
........................................................................................................................
(1)
The graph shows the students’ results.
(c)
Explain the shape of the graph between 22 °C and 27 °C.
........................................................................................................................
........................................................................................................................
........................................................................................................................
Page 86
........................................................................................................................
(2)
(d)
A farmer wants to grow lettuces as quickly and cheaply as possible in winter.
(i)
At what temperature should he keep his greenhouse to grow the lettuces as
quickly and cheaply as possible?
............................ °C
(1)
(ii)
Explain the reason for your answer.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(Total 8 marks)
Q57.
Energy is obtained from both aerobic and anaerobic respiration during exercise.
(a)
Give three differences between aerobic and anaerobic respiration.
1 .....................................................................................................................
........................................................................................................................
2 .....................................................................................................................
........................................................................................................................
3 .....................................................................................................................
........................................................................................................................
(3)
Page 87
(b)
Two students did the same step-up exercise for 3 minutes.
Thinkstock.com
One of the students was fit. The other student was unfit.
The graph shows how the students’ heart rate changed during the exercise and after
the exercise.
Page 88
(b)
Suggest which student was the fitter.
Draw a ring around your answer.
Student X / Student Y
Give three reasons for your answer.
1 .....................................................................................................................
........................................................................................................................
2 .....................................................................................................................
........................................................................................................................
3 .....................................................................................................................
........................................................................................................................
(3)
(c)
Explain the advantage to the students of the change in heart rate during exercise.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(4)
(Total 10 marks)
Q58.
During evolution, many groups of animals have become extinct (died out).
Page 89
(a)
The graph shows how the number of animal groups has changed over time.
Harold L Levin, The Earth Through Time,© 2005,
Reprinted with permission of John Wiley & Sons, Inc.
How has the number of animal groups changed between 200 million years ago and
the present day?
........................................................................................................................
........................................................................................................................
(1)
(b)
In this question you will be assessed on using good English, organising information
clearly and using specialist terms where appropriate.
Describe the different causes of the extinction of organisms.
Your description should include possible reasons for the mass extinctions shown on
the graph.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
Page 90
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(6)
(Total 7 marks)
Q59.
The diagram shows how cells from human embryos can be used to grow
‘replacement body parts’ for humans.
Sue Medaris/University of Wisconsin-Madison
(a)
Complete the following sentences.
(i)
The fertilised egg has ................................. sets of genetic information.
(1)
(ii)
The fertilised egg divides to form the 5-day-old embryo by a process
called ................................................................
(1)
Page 91
(b)
Some statements about stem cells are given below.
Tick ( ) two advantages and two disadvantages of using stem cells to grow
‘replacement body parts’ for humans.
Advantage
Tick ( )
Disadvantage
Tick ( )
Stem cells can grow into many different kinds
of body cells.
Stem cells may grow out of control.
Large numbers of stem cells can be grown in
the laboratory.
Stem cells may be used to treat some human
diseases.
Collecting and growing stem cells is expensive.
Patients treated with stem cells may need to
take drugs for the rest of their life to prevent
rejection.
(4)
(Total 6 marks)
Q60.
Some students investigated the effect of nitrates on the growth of seedlings.
The diagram shows the apparatus the students used.
Page 92
The students set up three test tubes.
•
Tube A contained pure water
•
Tube B contained all the mineral salts that a seedling needs for healthy growth
•
Tube C contained all the mineral salts that a seedling needs for healthy growth,
but no nitrate.
(a)
Why did the students set up tubes A and B?
........................................................................................................................
........................................................................................................................
(1)
(b)
To make it a fair test, what should each of the tubes, A, B and C, contain?
........................................................................................................................
........................................................................................................................
(1)
The table shows the students’ results.
Tube
A
B
C
(c)
Solution in test tube
Mass of seedling
after 14 days
in g
Pure water
0.10
All the mineral salts a seedling needs for healthy growth
0.45
All the mineral salts a seedling needs for healthy growth but
no nitrate
0.30
Give two conclusions that you can make from the students’ results.
1 .....................................................................................................................
Page 93
........................................................................................................................
2 .....................................................................................................................
........................................................................................................................
(2)
(Total 4 marks)
Q61.
In humans, sex chromosomes control whether a person is male or female.
(a)
Use letters X and Y to complete the Punnett square for sex inheritance.
Eggs
or
Sperm
or
XX..........
............................
............................
............................
...........
(3)
(b)
A couple already have three boys.
What is the probability that their next child will be a girl?
........................................................................................................................
........................................................................................................................
(1)
(Total 4 marks)
Page 94
Q62.
The diagrams show one of Mendel’s experiments.
He bred pea plants.
Mendel suggested that flower colour was controlled by inherited factors.
Draw a ring around the correct answer to complete the following sentences.
dominant.
(a)
The first generation plants show that the red factor is
environmental.
recessive.
(1)
(b)
The second generation plants show that the white factor is
Page 95
dominant.
environmental.
recessive.
(1)
(c)
What do we call inherited factors?
........................................................................................................................
(1)
(d)
How are inherited factors passed from generation to generation?
........................................................................................................................
(1)
(Total 4 marks)
Q63.
A class of students was set the task of estimating the number of dandelions on the
school field.
To do this, they decided to use sampling squares called quadrats.
Each quadrat had an area of 1 m2.
The diagram shows the dimensions of the school field.
Page 96
(a)
Which is the best way of using quadrats in this investigation?
Tick ( ) one box.
Tick
( )
Statement
Place all the quadrats where there are lots of plants.
Place all the quadrats randomly in two different sample areas.
Place all the quadrats where all four types of plant are growing.
(1)
(b)
Each student collected data by using 10 quadrats.
These are the results for one student, Mary.
Quadrat number
Number of dandelions
1
3
2
3
3
6
4
2
5
1
6
2
7
0
8
3
9
2
10
0
Calculate the mean number of dandelions per quadrat counted by Mary.
Show clearly how you work out your answer.
........................................................................................................................
........................................................................................................................
Mean number of dandelions ............................
(2)
Page 97
(c)
Another student, Sharon, calculated a mean of 2.8 dandelions per quadrat from her
results.
Estimate the number of dandelions in the whole field by using:
•
a mean of 2.8 dandelions per quadrat
•
information from the diagram on the opposite page
•
the equation below.
Show clearly how you work out your answer.
estimated number of
dandelions on field
=
mean number of dandelions number of quadrats that would fit into
×
per quadrat
the field
........................................................................................................................
........................................................................................................................
Estimated number of dandelions ...............................
(2)
(Total 5 marks)
Q64.
Babies find it difficult to digest proteins in their food.
Thinkstock.com
Baby food manufacturers use enzymes to ‘pre-digest’ the protein in baby food.
(a)
Use words from the box to complete the following sentences.
Page 98
amino acids
amylases
proteases
glucose
fatty acids
lipases
Proteins are ‘pre-digested’ using enzymes called .........................................
The pre-digestion of protein produces ...........................................................
(2)
(b)
A baby food manufacturer uses enzyme V to pre-digest protein.
He tries four new enzymes, W, X, Y and Z, to see if he can reduce the time taken to
pre-digest the protein.
The graph shows the time taken for the enzymes to completely pre-digest the
protein.
The manufacturer uses the same concentration of enzyme and the same mass of
protein in each experiment.
(i)
How long did it take enzyme V to pre-digest the protein?
................ minutes
(1)
Page 99
(ii)
Which enzyme, V, W, X, Y or Z, would you advise the baby food manufacturer
to use?
Enzyme
(1)
(Total 4 marks)
Q65.
The drawing shows the cell of a bacterium.
(a)
List A gives the four structures labelled on the diagram.
List B includes information about each structure.
Draw one line from each structure in List A to the correct information about the
structure in List B.
List A
Structure
List B
Information
Page 100
(4)
(b)
Give two differences between an animal cell and the cell of a bacterium.
1 .....................................................................................................................
2 .....................................................................................................................
(2)
(c)
The diagrams show cells containing and surrounded by oxygen molecules.
Oxygen can move into cells or out of cells.
Page 101
Into which cell, A, B, C or D, will oxygen move the fastest?
Write the correct letter, A, B, C or D, in the box.
(1)
(d)
Complete the following sentence.
Oxygen is taken into the cell by the process of .............................................
(1)
(Total 8 marks)
Page 102
M1.
(a)
A cytoplasm
1
where (chemical) reactions take place
do not accept where cell functions take place
1
or
carries/holds the organelles/named organelles / named chemicals (including
nutrients)
do not accept keeps the shape of the cell
or
contains water
or
presses out on the membrane
allow: keeps cell turgid
allows transport through the cell
B membrane
do not accept by themselves:
protects cell
gives shape
1
controls what enters/leaves the cell
1
or
contains the cell/holds the cell together
do not accept keeps harmful substances out
or
allows movement into and out of the cell C nucleus
1
contains the genetic
Page 103
material/DNA/genes/chromosomes
do not accept:
brain of the cell
stores information/instructions
tells cell what to do
or
controls (the activity) of the cell
1
(b)
(i)
one mark for each correctly labelled part
cell wall
do not accept anything inboard of the inner edge vacuole
accept anything inboard of transplant
chloroplast: site of photosynthesis/ for photosynthesis
accept word equation or balanced equation
1
cell wall: supports the cell/keeps the shape/keeps it rigid
do not accept protects the cells
2
(ii)
vacuole: acts as reservoir for water / chemicals/(cell)/sap
3
or
keeps cell turgid/pushes content to
edge
or
maintains concentration gradient
or
allows cell elongation (not growth)
1
[12]
M2.
(a)
genes/DNA
1
female/girl/woman/
Page 104
both required in the correct place for this last mark
male/boy/man/
do not accept homo/heterogametic, homo/heterozygous
1
(b)
parents correct
n.b if parents are wrong, candidates can score a maximum
of 3 marks
1
gametes correct
allow just 1 mark for female
1
combinations correct
1
correct analysis of the 50:50 ratio of what is written
1
[6]
M3.
(a)
carbon dioxide/CO2
1
(b)
through the roots/root hairs
do not accept leaves
1
(c)
oxygen
1
sugar/glucose/other named sugar/starch/carbohydrate
1
(d)
award one mark for each mark point
n.b. accept chloroplast for chlorophyll
n.b. credit the candidate who answers in terms of the white
Page 105
areas of the leaf
chlorophyll is green
e.g. green areas have chlorophyll
1
chlorophyll/green is needed for photosynthesis
e.g. it is only in green areas that
photosynthesis can take place
after this point do not penalise a candidate if they do not
refer to photosynthesis
1
light is needed
e.g. it does not happen in the dark
do not accept sunshine/sun
1
photosynthesis produces/makes starch
e.g. starch is made
so
e.g. ‘you need light to make starch’ scores 3rd and 4th
marking points
‘you need chlorophyll and light for photosynthesis’ scores on
the 2nd and 3rd marking points
‘photosynthesis makes starch and you need green leaves
and light for it to work’ scores
on the 2nd, 3rd and 4th marking points
1
[8]
M4.
(a)
(i)
count the pulse or count beats in artery in wrist neck or feel the pulse or
take the pulse or find the pulse
accept use of heart monitor or heart meter
1
(ii)
80
Page 106
2 marks for correct answer
1f answer incorrect allow 1 mark for showing 8000 divided by
100 or indicating cardiac output divided by stroke volume
2
(iii)
Increased activity stroke volume
falls / gets less / should get higher / reach a peak
accept does not increase or changes from 134 cm3 to 127
cm3
1
(iv)
1ncreased / more ventricle contractions
accept heart beat faster or it beats faster or more powerful
contractions
1
(b)
(stronger heart muscle) increases cardiac output or increases stroke volume
accept pumps more blood (per beat) or pumps blood faster
ignore heart bigger
1
so more (oxygenated) blood can be sent to muscles
accept more oxygen sent to muscles
1
[7]
M5.
any four from:
more energy / respiration required
accept it prevents / reduces anaerobic
respiration or less / no lactic acid
reference to increase must be made,
but only needed once, provided
inference is clear for remainder of points.
accept ‘delivered more quickly’ for ‘increase’
increase oxygen uptake into blood (in lungs)
increase oxygen delivery to muscles
Page 107
increase glucose delivery to muscles
increase removal of heat from muscles or increase delivery of heat to skin
increase removal of carbon dioxide from muscles
increase removal of carbon dioxide from blood (in lungs)
[4]
M6.
(a)
(before exercise) – 9 to 11 and (after exercise) – 12 or 13
both correct
1
(b)
0.75 to 0.90
ignore working or lack of working
eg. 2.35 – 1.55 or
for 1 mark
or other suitable figures
2
(c)
any four from:
still need to remove extra carbon dioxide
still need to remove heat / to cool
(some) anaerobic respiration (in exercise)
lactic acid made (in exercise)
oxygen needed to break down lactic acid or suitable reference to oxygen debt
lactic acid broken down to CO2 and water or lactic acid changed into glucose
4
[7]
Page 108
M7.
(a)
(i)
Aa or aA
1
(ii)
allele / gene for vestigial wings / a is recessive
or vestigial is recessive or A is dominant or
A would override the effect of a or A present gives long wings
1
(b)
parental genotypes correct – both Aa
NB can pick up chain of logic at any point correctly
derived from candidate’s previous point
1
gametes correctly derived from P genotypes
1
offspring genotypes correctly derived from gametes
1
3:1 ratio recognised
wrong cross and not 3:1 ratio = max 2
1
[6]
M8.
(a)
(i)
liver
1
(ii)
on diagram:
‘X’ on liver
must be unambiguous (eg not overlapping gall bladder)
intersection of X in liver
1
(b)
stomach
1
small intestine
accept duodenum or ileum
extra wrong answers cancel the mark,
eg small intestine (colon) = no marks
1
Page 109
(c)
amylase not produced by stomach
accept no starch digesting enzymes in the stomach
accept correct enzyme not in stomach
accept only proteases in stomach
do not accept protease does not digest starch
1
acid / low / wrong pH in stomach or enzyme would be denatured in
stomach or amylase only works in neutral / alkaline conditions
incorrect extra information cancels mark
do not accept amylase does not work in the stomach
1
[6]
M9.
(a)
respire
1
2
blood
1
2
[6]
M10.
(a)
one from each parent / one from egg and one from sperm
do not accept egg and sperm join / fertilisation unqualified
1
(b)
(i)
nn
accept a ring around printed nn
1
(ii)
Nn
Nn
1
Page 110
[3]
M11.
(a)
chromosome
accept chromosomes
1
(b)
drawing shows:
1
just 2 chromosomes
one long + one short
1
[3]
M12.
(a)
(i)
protease
accept peptidase or named protease
e.g. pepsin / trypsin
allow ‘proteinase’
1
(ii)
amino acids
accept peptides / polypeptides / peptones
1
(b)
points plotted accurately
±
square
deduct 1 mark per error
2
best fit curve or ruled point-to-point
if double line within
square
Page 111
allow sharp apex
do not allow single straight line
if no points line defines points
if (5,0) not plotted only penalise 1 mark
bar graph wide bars – no marks
bar graph ±
square max 2 for points
1
(c)
(i)
2 or correct from candidate’s graph
±
square
1
(ii)
stomach
1
(d)
proteins are large / product is small
1
proteins (may be) insoluble / product is soluble
1
cannot be absorbed / cannot enter blood or cannot pass through gut lining
accept reverse referring to product
1
[10]
M13.
(a)
(i)
A = nucleus
1
B = (cell) membrane
1
(ii)
(cell) membrane
1
(b)
70
if correct answer, ignore working or lack of working
Page 112
for 1 mark
2
[5]
M14.
(a)
lipase
1
(b)
fatty acid
ignore glycerol
1
(c)
(i)
0.25 or
if correct answer ignore working or lack of working
for 1 mark
2
(ii)
fats emulsified or described re. Small droplets or large S.A.
(for enzyme action) or fats ‘mix’ better with water
do not allow breakdown / breakup unqualified
1
[5]
M15.
(a)
A = meiosis
accept ‘mieosis’
do not accept ‘miosis’
1
Page 113
B = mitosis
do not accept ‘meitosis’ etc
1
(b)
fertilisation allow conception
1
(c)
(i)
23
1
(ii)
46
1
[5]
M16.
(a)
(i)
L.H.S. – water / H2O
1
R.H.S. – oxygen / O2
accept H2O
accept O2 / O
1
(ii)
chlorophyll
must make it clear that it is the chlorophyll
do not credit chloroplast on its own
do not accept chloroplast / chlorophyll
without indication that it is chlorophyll
1
(b)
(i)
light intensity / temperature is high enough for higher rate or light /
temperature is not limiting
1
low CO2 available or not enough CO2
available or rate would be higher with more CO2
1
(ii)
temperature
allow water / rain
Page 114
allow (too) cold / hot as a minimum
allow wave length / frequency / colour
ignore ions
ignore heat
1
[6]
M17.
(a)
in sequence
starch
1
sugar
1
protein
1
amino acids
1
(b)
(too) large or insoluble
do not accept “breaking up”
do not accept complex
accept ‘need to make molecules
smaller / soluble’ – reverse argument
1
cannot be absorbed or
cannot enter blood or
cannot pass through wall / lining of
intestine / gut or villi
“body” not enough
not large intestine
1
(c)
mouth
accept positive indication
1
(d)
enzymes
Page 115
allow catalysts
do not accept catalase
1
[8]
M18.
in the correct order
DNA
1
23
1
XX
1
XY
1
recessive
1
dominant
1
[6]
M19.
(a)
fossils / teeth / bones / skeleton / foot prints
allow cave drawings
do not accept scientists have seen
them
1
(b)
only (some) bones remain / soft parts have decayed
accept ‘no-one has ever seen one’
allow no photos, no pictures, no drawings
1
Page 116
(c)
any two from:
•
hunted by human
•
(new) predator
allow more predators
•
(new) competitor
•
(new) disease
•
environment changed / named environmental change
allow natural disaster
•
prey extinct / loss of food supply
ignore not enough food
2
[4]
M20.
(a)
(i)
20
1
(ii)
12000
1
(b)
area of strips
or
length / width_ / size of transect
or
number of transects
1
(c)
(i)
since squirrels mobile
or
squirrels could be counted twice
or
Page 117
squirrels hide
1
(ii)
any two from:
•
numbers of larders observed likely to be lower than actual
do not accept squirrels share larders
or squirrels have more than one larder
•
since unlikely that all could be spotted if 5 m away
•
old larder
•
squirrels moved on / died
•
young squirrels
•
haven’t made a larder
2
(d)
(i)
0 to 6.8
1
(ii)
any one from:
do not accept squirrels prefer blue spruce
•
squirrels prefer blue spruce cones / seeds / nuts as food
•
more cones / food
•
more nesting sites
•
fewer predators / competitors
1
[8]
M21.
(a)
increased speed
or harder exercise / running
→increased need / use / loss of energy
1
allow further you run / walk the more energy you need
increased mass / bigger → increased use of energy
1
Page 118
(b)
any three from:
•
supply / using (more / enough) oxygen
or get (more) oxygen in blood(*)
•
remove (more) CO2(*)
•
doing (more) work
or
using (more) energy allow produce energy(*)
(*)need reference to ‘more’ ONCE only for full marks
•
for respiration
•
prevent build up of lactic acid
or prevent oxygen debt
or prevent anaerobic (respiration)
or allow aerobic (respiration)
3
[5]
M22.
A = nucleus
1
B = cell wall
1
[2]
M23.
(a)
any three from:
•
((mean) mass) increases up to 7 / 8 units (of light) then levels off
•
light limiting factor up to 7 / 8 units
•
for photosynthesis
must be in correct context
•
other factor / temperature limiting above 7 / 8 units
3
Page 119
(b)
any two from:
•
cost of providing conditions / heat / light / CO2
•
effect of treatment on profit
allow too much of factor is wasteful
•
relevant use of data from graph eg limiting factors
•
named other factors eg fertiliser / pest control / weeds /
density of planting
allow taste / appearance
2
(c)
nitrate function
produce amino acids / proteins / enzymes
ignore DNA
do not allow chlorophyll
1
nitrate deficiency
stunted growth
allow description
ignore plant dies
1
magnesium function
produce chlorophyll
ignore chloroplasts
1
magnesium deficiency
yellow leaves / plant
ignore plant dies
1
[9]
M24.
(a)
any two from:
•
to combine / use amino acids
Page 120
do not allow to make amino acids
•
in specific / particular / correct / right order
•
to manufacture protein / enzymes / hormones
allow examples of proteins / enzymes / hormones
2
(b)
(i)
(man) B
no mark for this but max 2 marks if A given
any three from:
•
child gets DNA / bars / lines from mother and father / parents
ignore genes / chromosomes
•
(child has) mother’s 25 / 28 / 30 / 31
or child gets 17 / 19 / 22 / 24 from mother
•
(child has) man B’s 10 / 12 / 13 / 14
or child gets 18 / 20 / 21 / 23 from B
contradictions disqualify 2nd and / or 3rd marking points
ignore genes / chromosomes
•
no bars / DNA / lines from man A correspond to child
3
(ii)
any two from:
•
gametes / eggs / sperm
•
contain only half of (mother’s / father’s) DNA /
chromosomes / genes / genetic information
•
due to meiosis
2
[7]
Page 121
M25.
(a)
cell membranes
1
(b)
(i)
two recessive / cystic fibrosis / faulty / diseased / the allele(s) / genes
two can be implied by second marking point
ignore chromosomes
1
from Bob and Carol / both parents / the parents
if no other marks awarded ‘Carol is a carrier’ gains 1 mark
1
(ii)
(inherited) dominant / normal allele / gene
1
from Carol / mother
ignore references to recessive allele / gene from father / Bob
if no other marks awarded he has just / only one recessive
allele gains 1 mark
1
(c)
(i)
reduce number of people with cystic fibrosis (in population)
or
reduce health-care costs
or
expensive to have baby with cystic fibrosis
accept to allow decision / emotional argument qualified
eg allows abortion
or
allows people to make choices about termination
or
help to prepare financially / emotionally etc
1
(ii)
any one from:
•
possible damage / risk to embryo / fetus / baby
Page 122
allow possible harm / risk to mother
•
screening / it is expensive
•
(may) have to make ethical / moral / religious decisions
ignore not natural / playing God / unethical / immoral /
religious unqualified
•
right to life
1
[7]
M26.
(a)
lipase
allow phonetic spelling
allow lipidase
1
(b)
(i)
fall then rise owtte eg down then up
allow faster then slower
ignore explanations
1
minimum / least / fastest / best / optimum at 39–41(°C)
allow it falls to 40(°C)
if no other marks gained, ‘falls to an optimum’ gains 1 mark
1
(ii)
(yes)
there is no mark for circling ‘yes’
maximum 1 mark if No is circled
any two from:
•
less heat / energy / electricity / power required /
used / wasted
ignore lower temperature
•
conserves fuel supplies
or less fuel used
•
less pollution from power stations
owtte
Page 123
accept less global warming
or
less CO2 / carbon emissions / greenhouse gases
or
less SO2 / acid rain
NB only direct effects
less pollution only is not enough
2
(c)
any two from:
max 1 mark for reference to cell
•
enzyme / lipase
accept any named enzyme
•
destroyed / denatured
allow damaged / broken down
not ‘killed’
•
reference to (specific) shape changed
ignore detergent / it
2
[7]
M27.
(a)
photosynthesis
1
(b)
oxygen
1
(c)
chlorophyll
1
(d)
starch
1
[4]
Page 124
M28.
(a)
A nucleus
1
B (cell) membrane
1
C cytoplasm
1
(b)
(i)
it is thin
1
(ii)
diffusion
1
[5]
M29.
(a)
any three from:
•
rose rapidly (during exercise) / use of approximate figures
•
then more slowly (during exercise)
accept rate (of increase) slows down
•
to max 126 / at 5 minutes / end of exercise
•
rapid fall (during recovery) or use of approximate numbers
•
then less rapid fall / use of approximate numbers
•
returned to resting rate (60 bpm) by 11 minutes
3
(b)
arteries dilate / widen
accept muscle in wall relaxes
1
(c)
Page 125
4
[8]
M30.
(a)
any two from:
•
neutralises acid / makes conditions alkaline / raises pH
•
enzymes (in small intestine) work (more/most effectively)
or stop/prevents enzymes being denatured
•
emulsifies fats/lipids or description of emulsification
do not accept breakdown unqualified
•
larger surface area
2
(b)
(i)
bile / bilirubin / pigment / broken down haemoglobin /
substance / cholesterol linked to movement or effect
1
does not get to the intestine / food / faeces
or cannot leave liver or effect not happening (in intestine)
1
(ii)
bilirubin / pigment / broken down haemoglobin
not ‘bile’ alone
1
(deposited) in skin
only award if bilirubin / pigment / broken down haemoglobin
Page 126
given
allow carried in the blood
1
[6]
M31.
(a)
any two from:
accept other logical / reasonable ideas
•
other scientists not aware of his work
•
chromosomes / DNA / genes not seen / discovered / known
do not accept there was no interest in genetics
•
other theories accepted at the time
•
not considered to be a scientist / not eminent / respected
allow ‘he was just / only a monk’
2
(b)
(i)
random selection
accept a method of achieving random selection
eg “take a handful”
if number given, minimum 20
1
(ii)
any one from:
•
1:1 / one to one
•
19:21
accept any ratio to give correct answer, eg “50:50”
do not accept 21:19 unqualified
1
(iii)
A + a as gametes from 1st parent
1
a + a as gametes from 2nd parent
allow a alone
1
Page 127
(offspring / 2nd generation) Aa aa
offspring must be derived from correct gametes
correct identification of yellow (Aa)
other symbols correctly used can gain full marks
1
or
green (aa) (if both given, both must be correct)
ignore references to previous generations
if no other marks awarded, both correct parental genotypes
given gains 1 mark
examples of award of first three marks
1
[8]
M32.
(a)
A carbohydrase
1
Page 128
B isomerase
1
(b)
less needed (to get same effect)
1
(c)
(i)
they all work at atmospheric pressures
1
they work well at 25 – 45 °C
accept any clear indication of correct statement(s) identified
1
(ii)
any two from:
•
they are easily broken down by high temperature or the wrong pH
•
they are soluble in water, so it may be difficult to separate them from
products
•
they are expensive to buy
accept any clear indication of correct statement(s) identified
accept for 2 marks if written as two separate disadvantages
2
[7]
M33.
(a)
(i)
both correct = 2 marks
Page 129
one correct = 1 mark
extra line from a statement cancels the mark
2
(ii)
1st space: carbon dioxide
allow CO2 (ignore superscript)
do not allow CO alone
1
2nd space: glucose / sugar / starch / carbohydrate
1
(b)
(i)
any one from:
•
move lamp or change distance between lamp and plant
ignore measure the distance
•
change wattage / power of (light) bulb
do not accept just “change bulb”
•
change voltage / power supply to the (light) bulb
•
change the number of lamps
•
put translucent material between lamp and plant
accept examples, eg tracing paper / filters
do not accept coloured filters
1
(ii)
rises
1
levels off
ignore numbers
1
(iii)
idea that it levels off
or
does not increase at all light intensities
or
it only increases to a certain amount
answers should relate to photosynthesis and not to bubbling
1
Page 130
[8]
M34.
(a)
characteristics
1
(b)
genes
1
(c)
chromosomes
1
(d)
mitosis
1
(e)
asexual
1
[5]
-
M35.
(a)
A
nucleus
1
B
(cell) membrane
1
C
cytoplasm
1
(b)
any two from:
•
(contain mitochondria
•
many (mitochondria)
•
respiration (occurs in mitochondria)
2
[5]
Page 131
M36.
(a)
any four from:
•
mutation / variation
•
produces smaller wings / fatter body
must be linked to mutation / variation
•
wings no longer an advantage since no predators
allow wings / flight not needed as no predators
•
wings no longer an advantage since food on ground
allow wings / flight not needed as food on ground
•
fatter body can store more energy when fruit scarce
•
successful birds breed / pass on genes
4
(b)
any one from:
•
evidence has all gone
•
no scientists on island at time to record evidence
•
no records (from sailors)
1
[5]
M37.
(a)
(i)
B
1
(ii)
any one from:
•
largest area of / most digestion (of lipid)
allow agar / jelly / mixture broken down / digested
do not allow digestion of bacteria / lipase
ignore digestion by bacteria
Page 132
•
largest clear area
1
(b)
any two from:
•
effect of pH / pH described
•
effect of temperature
•
effect on different types of lipid / fat
•
cost or allergic reactions or effect on skin / fabrics / or
environment or interaction with other chemicals in
powder or shelf life
2
(c)
enzymes / named enzyme denatured / destroyed
allow active site(of enzyme) altered
1
[5]
M38.
(a)
(i)
water / H2O
allow hydrogen oxide
1
oxygen / O2 / O
allow upper and lower case symbols and superscripts
answers must be in this order
1
(ii)
respiration in the plant
allow clear indication of correct response
1
(b)
light (: no light) / light intensity
ignore references to the card / covered / uncovered
1
chlorophyll (: no chlorophyll) / chloroplast
Page 133
allow leaf colour or both green and white given
1
(c)
(i)
no light (received) or it’s dark
allow no photosynthesis
do not allow little light / photosynthesis
ignore sun
apply list principle for other factors
1
(ii)
no chlorophyll / chloroplasts (present)
allow no / little photosynthesis
allow white or not green or little chlorophyll / few
chloroplasts
apply list principle for other factors
1
[7]
M39.
(a)
chromosomes
1
(b)
diagram showing four separate chromosomes two long and two short
(as in diagram 1)
allow each chromosome shown as two joined chromatids
do not allow if chromosomes touching each other
1
(c)
(i)
any two from:
•
can grow into any type of tissue / named tissue
•
used in medical research
•
used to treat human diseases
•
large numbers can be grown
2
(ii)
any two from:
Page 134
•
expensive
•
grow out of control / ref cancers
•
may be rejected
•
need for drugs (for rest of life)
2
[6]
M40.
(a)
A
1
(b)
(i)
diffusion
1
(ii)
respiration
1
(iii)
mitochondria
1
(iv)
photosynthesis
1
[5]
M41.
(a)
it has many chloroplasts.
1
(b)
(has) cell wall
1
(has) vacuole or large / permanent vacuole
do not allow chloroplasts
assume plant cell throughout
accept converse for animal cell
1
[3]
Page 135
M42.
(a)
(i)
19 800
for correct answer ignore working or lack of working
165 × 120 but no answer / wrong answer = 1 mark (ignore
extras)
2
(ii)
any two from:
•
for respiration
ignore oxygen debt
•
energy released
allow energy produced
•
prevents anaerobic respiration
•
prevents build-up of lactic acid
2
(b)
any two from:
•
increased breathing rate(*)
•
increased depth of breathing or deep breathing(*)
(*)more breathing is max 1 mark
ignore increase in heart rate
allow heavier breathing
do not allow harder breathing
•
dilation of arteries / vasodilation
allow blood vessels dilate
do not allow veins / capillaries dilate
•
blood diverted from elsewhere
ignore name of organ
2
[6]
Page 136
M43.
(a)
1 in 4 / 1/4 / 1: 3 / 25% / 0.25
do not accept 3:1 / 1:4 / 2:6
1
(b)
either from C and D
accept synonyms for dominant / recessive eg
Normal / faulty
accept genetic diagram if clearly referring to correct
individuals or genotypes on family tree
allow ‘gene’ for ‘allele’
any three from:
•
C and D have disorder
ignore ‘C & D are carriers’
•
I/J don’t have disorder
•
C and D have dominant and
recessive alleles
•
recessive alleles from C and D passed to I/J
or I/J have two recessive alleles
NB if allele was recessive then all offspring of C and D would
have the disorder = 3 marks
or from A and B
assume response refers to A + B unless contradicted
•
A is homozygous recessive / rr, and B is heterozygous / Rr can be shown
in words or symbols
allow any symbol
•
offspring can be rr or Rr described
allow without key
3
(c)
(i)
(embryos) checked for inherited / genetic disorders / conditions
accept diseases for disorders
1
(ii)
any three from:
•
C/D have disorder / have dominant allele
accept disease / condition
accept ‘gene’ for ‘allele’
ignore reference to ‘carriers’
Page 137
•
chance of embryo / foetus / child having disorder
or may pass on alleles for disorder to their offspring
•
C/D might want to decide on termination or prepare
for child with disorder
•
G and H don.t have disorder / both homozygous
recessive / have no dominant alleles (for this disorder)
•
so offspring (of G and H) cannot / don.t have disorder
3
[8]
M44.
(a)
opaque / less transparent / blue
allow mixture becomes dark / black
ignore thicker
1
(b)
(i)
7 (minutes) or in range 6.7 to 7
award 2 marks for correct answer
if answer is incorrect evidence of selection of
40(% light intensity) either in working or in graph
2 for 1 mark
2
(ii)
any two from:
•
slower / takes longer at lower temperatures
•
(40oC is) optimum / best temperature
allow near to 37oC / body
temperature where enzymes work best
•
enzyme denatured / destroyed / damaged at higher temperatures
allow description of denaturation
2
(c)
(i)
isomerase
allow phonetic spelling
1
Page 138
(ii)
fructose is sweeter than glucose
needed in smallerquantities or less is needed
2
[8]
M45.
(a)
any one from:
•
(type of / amount of) soil / minerals / nutrients / pH
•
amount of water / time of watering
•
space between plants / plants and wall
•
time for growth
list principle
ignore carbon dioxide / same number of plants / food
do not allow temperature / light / exposure to wind
1
(b)
(i)
North wall
1
(ii)
nugget
list principle
1
(c)
has not tested all varieties / nugget / champion against all walls
do not allow repeat experiment
1
[4]
M46.
(a)
2 and 3
1
(b)
cell P has an X chromosome; cell R has a Y chromosome
Page 139
1
(c)
any two from:
•
(formed from) different egg / 2 eggs
•
(formed from) different sperm / 2 sperm
•
have different genes / alleles / chromosomes / DNA
allow genetics
2
(d)
(i)
stem cells
1
(ii)
the cells divide
1
the cells differentiate
1
(iii)
(medical) research / named eg growing organs
or
medical / patient treatment
allow (embryo) cloning
do not allow designer babies / more babies
1
(iv)
any one from:
•
ethical / moral / religious objections
ignore cruel / not natural / playing God
•
potential harm to embryo
allow deformed
ignore harm to mother
1
[9]
M47.
(a)
microorganisms
1
Page 140
(b)
(i)
proteases clear indications of correct answer
1
(ii)
amino acids (both words) clear indications of correct answer
1
(c)
(i)
14
1
(ii)
mark independently
enzyme Z
clear indication of correct answer
1
takes least time (to pre-digest protein) / works fastest
allow only 7 minutes / less time / faster
do not allow works best
1
(iii)
temperature
1
pH
1
[8]
M48.
(a)
(i)
A cytoplasm
accept clear indications
1
B nucleus
1
(ii)
any two from:
two required for 1 mark
•
P
•
R
•
T
accept lower case letters
1
Page 141
(b)
sperm cells need a lot of energy to swim
1
[4]
M49.
(a)
there is a lack of valid / reliable evidence
1
because the early organisms were soft bodied or because remains were
destroyed by geological action
1
(b)
populations of salamanders became isolated / separated
1
by areas between mountains
1
there was genetic variation in these isolated communities
1
natural selection acted differently on these isolated communities
1
eventually resulting in interbreeding being no longer possible and so
new species have been formed
1
[7]
M50.
(a)
the enzyme must be lipase
1
since fatty acid produced, which lowered the pH
1
Page 142
(b)
(i)
0.25 or
correct answer with / without working
if answer incorrect / missing, then evidence of
gains 1 mark
2
(ii)
bile provides optimum / suitable / best pH for enzyme action
therefore the rate of the reaction increased
1
[5]
M51.
(a)
eggs produced by meiosis
1
therefore contain only half of mother’s DNA
1
(b)
(man B)
no marks
(child has) mother’s 25 / 28 / 30 / 31
or
child gets 17 / 19 / 22 / 24 from mother
1
(child has) man B’s 10 / 12 / 13 / 14
or
child gets 18 / 20 / 21 / 23 from B
1
no bars / DNA / lines from man A correspond to child
1
[5]
Page 143
M52.
(a)
(genotype / gametes from P / father) D and d (*)
1
(genotype / gametes from Q / mother) d and d / accept d(*)
1
offspring genotypes correctly derived from correct gametes(*)
1
offspring phenotypes R and S identified
1
(*) eg may be in punnett square
allow own upper and lower case symbols or
allow any symbol correctly used with key
(b)
Marks awarded for this answer will be determined by the
Quality of Written Communication (QWC) as well as the standard
of the scientific response.
No relevant content.
0 marks
There is a brief description of the issues involved in
screening for at least one condition.
Level 1 (1–2 marks)
There is some description of issues involved in screening
for both conditions but there is a lack of both pros and
cons for the two conditions.
Level 2 (3–4 marks)
There is a clear, balanced and detailed description of the
issues involved in screening for both conditions, giving
pros and cons for each condition.
Level 3 (5–6 marks)
examples of biology points made in the response
For cystic fibrosis
pros:
•
reduce number of people with cystic fibrosis (in population)
•
reduce health-care costs
•
allows decision / emotional argument,
eg allows people to make choices about termination
Page 144
cons:
•
possible damage / risk to embryo / fetus / baby
•
possible harm / risk to mother
•
(may) have to make ethical / moral / religious decisions
for polydactyly:
•
cures ‘disfigurement’
•
but condition not life threatening
•
so risks to foetus / mother unjustified
[10]
M53.
(a)
because stem cells can (be made) to differentiate
1
into nerve / muscle cells
1
(b)
ethical issues with destruction / damage to embryo
1
(c)
mitosis one cell division, meiosis two cell division
1
cells produced by mitosis have two sets of chromosomes,
cells produced by meiosis have one set of chromosomes
accept cells produced by mitosis are genetically identical,
cells produced by meiosis have some genetic differences
1
[5]
Page 145
M54.
(a)
area of strips / length of transects / number of transects
1
(b)
(i)
since squirrels are mobile and could be missed / counted twice
1
(ii)
numbers of larders observed likely to be lower than actual
do not accept squirrels share larders or squirrels have
more than one larder
1
since unlikely that all could be spotted if 5 m away or
old larders or
squirrels moved on / died
1
(c)
(no)
the bars show the range of the number of squirrel larders in
the different types of woodland
1
although spruce woodlands have the larger ranges, some
spruce woodlands will have very low numbers of larders
1
[6]
M55.
A – cell membrane
1
B– cytoplasm
1
C– genes / genetic material / chromosome
1
D – cell wall
1
Page 146
[4]
M56.
(a)
water
1
oxygen
1
in this order
(b)
keep temperature constant
1
(c)
a factor other than temperature is limiting
do not accept water
1
eg carbon dioxide
1
(d)
(i)
21/22
1
(ii)
rate of photosynthesis is at maximum
1
for the least heating cost
1
[8]
M57.
(a)
any three from:
•
oxygen used in aerobic respiration
Page 147
•
more energy from aerobic respiration
•
carbon dioxide and water are end products of aerobic respiration
•
lactic acid is end product of anaerobic respiration
3
(b)
(Student Y)
accept converse for student X
•
the lower resting heart rate
1
•
the lower heart rate increase and
1
•
the quicker recovery time
1
(c)
when exercising the rate of respiration (in the muscles) is higher
1
(the increased heart rate delivers)
•
more oxygen to the (respiring) muscles
1
•
more glucose to the (respiring) muscles
1
•
and results in faster removal of carbon dioxide and lactic acid
1
[10]
M58.
(a)
increased by about 7 times / from 600 to 4300 / by 3700
1
(b)
Marks awarded for this answer will be determined by the Quality
of Written Communication (QWC) as well as the standard of the
scientific response.
No relevant content
Page 148
0 marks
There is a brief description of at least two causes of
extinction, which has little clarity and detail.
Level 1 (1–2 marks)
There is a description of some causes of extinction,
including both small-scale and large-scale events but
there is a lack of clarity and detail.
Level 2 (3–4 marks)
There is a clear, balanced and detailed description of at
least five causes of extinction, including both small-scale
and large-scale events.
Level 3 (5–6 marks)
examples of biology points made in the response:
•
changes to the environment / named changes
•
new competitors
•
new diseases
•
new predators
•
volcanic eruptions
•
collisions with asteroids
[7]
M59.
(a)
(i)
two
1
(ii)
mitosis
1
(b)
Adv.
Stem cells can grow into many different kinds of
body cells.
Stem cells may grow out of control.
Page 149
Disadv.
Large numbers of stem cells can be grown in the
laboratory.
Stem cells may be used to treat some human
diseases.
Collecting and growing stem cells is expensive.
Patients treated with stem cells need to take drugs
for the rest of their life to prevent rejection.
1 mark for each correctly ticked advantage up to a maximum
of
2 marks
1 mark for each correctly ticked disadvantage up to a
maximum
of 2 marks
deduct 1 mark each for every incorrect box ticked in each
column up to a maximum of 2 deductions in each column
4
[6]
M60.
(a)
as control(s)
ignore fair test
1
(b)
the same volume of culture solution
1
(c)
plants with all mineral salts grew best
1
plants with mineral salts but no nitrate grow better than
without any mineral salts
1
[4]
Page 150
M61.
(a)
(X)
(XX)
XX
Y
XY
XY
1 mark for Y in sperm box
1 mark if XX box correct
1 mark if both XY boxes correct
3
(b)
1 : 1 or 50% or ½ or 0.5 or 1 in 2 or 1 out of 2 or 50 : 50
do not accept 50/50
accept equal (probability)
1
[4]
M62.
(a)
dominant
1
(b)
recessive
1
(c)
genes
1
(d)
gametes
1
[4]
Page 151
M63.
(a)
place all the quadrats randomly in two different sample areas.
extra boxes ticked cancels the mark
1
(b)
2.2
correct answer gains 2 marks
if answer incorrect, evidence of correct method gains 1 mark
allow only 1 mark for a rounded mean
2
(c)
15 120
correct answer gains 2 marks
if answer incorrect, evidence of correct substitution gains 1
mark
2
[5]
M64.
(a)
proteases
1
amino acids
1
(b)
(i)
14 minutes
1
(ii)
enzyme Z
1
[4]
Page 152
M65.
(a)
all four correct = 4 marks
three correct = 3 marks
two correct = 2 marks
one correct = 1 mark
extra line from a statement cancels the mark
4
(b)
any two from:
•
nucleus
•
no cell wall
•
separate chromosomes
2
(c)
A
1
Page 153
(d)
diffusion
1
[8]
Page 154