Q1.
(a)
A food contains protein. Describe, in as much detail as you can, what happens
to this protein after the food is swallowed.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(b)
The table shows the activity of lipase on fat in three different conditions.
CONDITION
UNITS OF LIPASE ACTIVITY PER MINUTE
Lipase + acid solution
3.3
Lipase + weak alkaline
solution
15.3
Lipase + bile
14.5
Explain, as fully as you can, the results shown in the table.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 7 marks)
Page 1
Q2.
The graph shows the effect of temperature on photosynthesis.
(a)
Between which temperatures is the rate of photosynthesis fastest?
............................... and .......................... °C
(1)
(b)
Suggest why the rate of photosynthesis stays the same between these two
temperatures.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
A greenhouse owner wants to grow lettuces as quickly and cheaply as possible in
winter.
At what temperature should he keep his greenhouse in order to grow the lettuces
as quickly and cheaply as possible?
Page 2
.......................... °C
Explain your answer.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 6 marks)
Q3.
The drawing shows a white blood cell ingesting a bacterium.
Label the parts of the white blood cell.
(Total 3 marks)
Q4.
Green plants make food in their leaves.
(a)
From where do the leaves get the energy that they need to make food?
Page 3
.....................................................................................................................................
(1)
(b)
The graph shows the effect of temperature on the rate of photosynthesis.
(i)
Between which temperatures is the rate of photosynthesis fastest?
.............................. and .............................. °C
(1)
(ii)
Suggest why the rate of photosynthesis stays the same between these two
temperatures.
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
(2)
(iii)
A greenhouse owner wants to grow lettuces as quickly and cheaply as
possible in winter.
At what temperature should he keep his greenhouse in order to grow the
Page 4
lettuces as quickly and cheaply as possible?
.............................. °C
Explain your answer.
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
(3)
(Total 7 marks)
Q5.
The table shows the amounts of carbohydrate, fat and protein in 100 g portions of five
foods,A - E.
MASS IN 100 g PORTION (g)
FOOD
CARBOHYDRATE
FAT
PROTEIN
A
0
1
20
B
50
2
8
C
0
82
0
D
12
0
1
E
20
0
2
(a)
A person eats 50 g of food E.
How much carbohydrate would the person eat?
................ g
(1)
(b)
Describe, in as much detail as you can, what happens to the protein after food A is
swallowed.
Page 5
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(Total 5 marks)
Q6.
The diagrams show four ways in which human twins may be formed.
Page 6
Which diagram, A, B, C or D, shows the process which will produce genetically identical
twin boys?
......................................................
Explain the reason for your choice.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
Page 7
...............................................................................................................................................
(Total 3 marks)
Q7.
The drawing shows some of the fossils found in the layers of rock in two cliffs.
The two cliffs are on opposite sides of a large valley.
Geologists think that the valley has been carved out by rivers, and that the order of rock
layers has not changed.
(a)
(i)
Which of the rock layers, A, B, C or D, is the oldest? ...................................
(1)
(ii)
Give the letters of two layers of rock on opposite sides of the valley that are
the same age.
.............................. and ..............................
(1)
(b)
How do fossils provide evidence for the theory of evolution?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 8
.....................................................................................................................................
(2)
(Total 4 marks)
Q8.
The drawing shows a white blood cell ingesting a bacterium.
(i)
Use words from the list to label the parts of the white blood cell.
cell membrane
cell wall
cytoplasm
nucleus
vacuole
(3)
(ii)
The scale shows that the white blood cell is 10 micrometres long.
How long is the bacterium? Show your working.
................... micrometres
(2)
(Total 5 marks)
Page 9
Q9.
Most people have a gene which produces a protein called CFTR that enables the
cells lining the lungs to work efficiently. In people suffering from cystic fibrosis this gene is
faulty; it produces a protein which lacks just one of the 1480 amino acids found in CFTR.
(i)
Name the molecule which carries the genetic information for producing proteins
such as CFTR.
.....................................................................................................................................
(1)
(ii)
Explain how this molecule is responsible for the structure of proteins such as
CFTR.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 4 marks)
Q10.
Read the extract.
Super-bug may hit the price of coffee
The coffee bean borer, a pest of the coffee crop, can be controlled by the pesticide
endosulphan However, strains of the insect that are up to 100 times more resistant to
the pesticide have emerged on the South Pacific island of New Caledonia.
For full resistance to be passed on to an offspring two copies of the new resistance allele
5
should be inherited, one from each parent. There is much inbreeding with brother-sister
matings happening in every generation, so it takes only a few generations before all the
Page 10
descendants of a single resistant female have inherited two copies of the resistance
allele.
If this resistance spreads from New Caledonia, it will mean the loss of a major control
10
method. This will present a serious threat to the international coffee industry.
(a)
Suggest how the allele for resistance to endosulfan may have arisen.
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
(i)
How would you expect the proportion of normal coffee bean borers on New
Caledonia to change over the next few years?
...........................................................................................................................
(ii)
Explain why this change will take place.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(c)
Explain why “it takes only a few generations before all the descendants of a single
resistant female have inherited two copies of the resistance allele.” (lines 6-8)
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 11
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 7 marks)
Q11.
In an investigation four groups of athletes were studied. The maximum rate of
oxygen consumption for each athlete was measured and the mean for each group was
calculated. The athletes then ran 10 mile races and the mean of the best times was
calculated for each group. The results are shown in the table below.
(i)
What is the relationship between maximum rate of oxygen consumption and time for
a 10 mile race?
.....................................................................................................................................
.....................................................................................................................................
(1)
(ii)
Suggest an explanation for this relationship.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 12
.....................................................................................................................................
(3)
(Total 4 marks)
Q12.
Coat colour in rabbits is controlled by one pair of genes. The allele for black coat (N)
is dominant to the allele for brown coat (n). The drawing shows the result of crossing a
black-coated rabbit with a brown-coated rabbit.
Complete the genetic diagram to show how the young rabbits inherited their coat colour.
Use the symbols N and n for the alleles. The alleles of the brown parent have been
inserted for you.
Page 13
(Total 3 marks)
Q13.
A student breathed out into an empty breathing bag five times.
Page 14
After breathing out five times the volume of air in the bag was measured.
The volume was 3000 cm3.
(a)
Complete the following sentences.
The air the student breathed in would contain more ........................................ than
the air the student breathed out.
The air the student breathed out would contain more ...................................... than
the air the student breathed in.
(2)
(b)
The student then did some exercise for two minutes. The volume breathed out in
five breaths was again measured. This time there was 9000 cm3 of air in the bag.
What does this tell you about the effect of exercise on breathing?
.....................................................................................................................................
.....................................................................................................................................
(1)
(c)
(i)
Name the chemical process that releases energy when it takes place in the
cells of the body.
................................................
(1)
(ii)
Name the substances produced by this process.
.......................................................... and ..........................................................
(2)
(iii)
Explain as fully as you can why this process has to take place more rapidly
during exercise.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
Page 15
(Total 8 marks)
Q14.
The drawing is an artist’s impression of some extinct plants.
(a)
Use only information from page 31 of the Data Book to help you to answer both
parts (i) and (ii) of the question.
These plants lived in forests. They died out at the end of the Carboniferous period.
(i)
How long ago did these plants become extinct? .................................... million
years.
(1)
(ii)
Suggest one reason why these plants became extinct.
...........................................................................................................................
...........................................................................................................................
(1)
Explain your answer.
Page 16
...........................................................................................................................
...........................................................................................................................
(1)
(b)
We know about these extinct plants from their fossils.
Describe how parts of plants become fossils.
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 4 marks)
Q15.
Wild turkeys have black feathers. Until about 30 years ago turkeys reared for meat
also had black feathers like this.
However, a recessive gene which produced entirely white feathers appeared, and turkey
farmers changed to breeding white-feathered birds.
Page 17
Supermarkets preferred white-feathered birds, because small pieces of feather left in the
skin after plucking were not visible as dark patches. Customers wanted unblemished
oven-ready birds. Now, however, there is a demand again for birds with black feathers
which can be marketed as ‘traditional’ farm-produced turkeys.
(a)
Feather colour is controlled by one pair of genes.
(i)
Suggest suitable symbols for each of the two alleles of this pair of genes.
Black feathers ........................
White feathers ..................................
(1)
(ii)
What alleles for feather colour would a white turkey have? ..........................
(1)
(b)
Explain carefully why ‘traditional’ black-feathered turkeys could not be bred from a
flock of white-feathered birds.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 4 marks)
Q16.
The graph shows the mean light intensity at different times of the year in an oak
wood.
Page 18
(a)
(i)
In which month would you expect the rate of photosynthesis in the oak trees
to be greatest?
.........................................................................
(1)
(ii)
There are plants living on the ground in the wood. In which month would you
expect their rate of growth to be fastest?
...........................................................................................................................
Explain your answer.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(b)
Name two factors, other than light intensity, that would affect the rate of
photosynthesis in the oak trees.
1 ..................................................................................................................................
2 ..................................................................................................................................
(2)
(Total 6 marks)
Page 19
Q17.
The picture shows the fossil remains of a bird.
(a)
Look carefully at the picture. Some parts of the bird were fossilised.
(i)
What were these parts made of?
...........................................................................................................................
(1)
(ii)
Explain why these parts have been preserved.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(iii)
How can you tell that this fossil was a bird? (You might find information from
Page 20
page 20 of the Data Book helpful.)
...........................................................................................................................
(1)
(b)
This bird lived about 140 million years ago. This type of bird is now extinct.
(i)
What does ‘extinct’ mean?
...........................................................................................................................
(1)
(ii)
Suggest one reason why this bird became extinct.
...........................................................................................................................
...........................................................................................................................
(1)
(iii)
Name one other example of an animal that became extinct many millions of
years ago.
...........................................................................................................................
(1)
(Total 7 marks)
Q18.
A student’s hobby was breeding pet mice. Three of the pet mice were called Stan,
Tom and Sharon. Stan and Tom had black fur. Sharon had white fur.
The colour of the fur is controlled by a single gene which has two alleles B and b.
(a)
The student first crossed Stan with Sharon. The results are shown on the diagram.
Page 21
Explain why the baby mice produced by crossing Stan and Sharon all had black fur.
You may use a genetic diagram if you wish.
(3)
(b)
The student then crossed Tom with Sharon. The results are shown on the diagram.
Page 22
When Tom was crossed with Sharon, some of the baby mice had black fur and
some white.
Explain why. You may use a genetic diagram if you wish.
(3)
(Total 6 marks)
Q19.
(a)
Complete the equation for photosynthesis.
(2)
(b)
The diagram below is printed in a plant care manual.
Use information from the diagram to answer the following questions.
Page 23
(i)
Name one type of plant which could live on the floor of a dense forest in the
middle of summer.
..........................................................................................................................
(1)
(ii)
Explain the reason for your answer to (i) above.
..........................................................................................................................
..........................................................................................................................
(1)
(iii)
The drawing shows one type of plant with variegated leaves.
The manual says that these plants need direct sunlight.
Suggest and explain why this plant needs ‘some direct sunlight’ in order to
develop satisfactorily.
..........................................................................................................................
..........................................................................................................................
(2)
(iv)
The drawing shows a cactus.
Page 24
Suggest and explain why cacti can only develop satisfactorily if they receive
full sunlight.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(Total 8 marks)
##
The following is adapted from an article which appeared in January 1994 in the Sunday
Times.
A woman gives birth at 59
Designer babies are just the first step in science’s ability to create a super race.
Test-tube baby techniques give doctors an unprecedented degree of control over the offspring
produced. When eggs and sperms are donated they seek to match the charactaristics of the donor
whose role has been replaced. As more is learned about the genetic contribution to charactaristics
such as intelligence, beauty or strength, this capacity to mix-and-match will increase.
Technological change frightens us when it is outside our control and when we fear how it might be
exploited by others. People wonder where the potential Brave New World of “retirement births” and
‘designer’ babies will ultimately lead us: cloning, genetic grading and even the introduction of animal
genes into humans. Unthinkable, perhaps, but entirely possible.
The techniques are there – in fact they have been for years. But who on earth would want to use
Page 25
them, apart from some power mad politician?
Use information from the article and any of your own knowledge to discuss the
arguments for and against allowing doctors to experiment with human fertilisation
techniques.
You will not receive marks for simply copying extracts from the article.
(Total 8 marks)
Q21.
Marathon runners are recommended to have a high carbohydrate diet prior to a
race. Three athletes tried out three dietary regimes prior to a marathon race.
These three dietry regimes were as follows.
Athlete A Up to 7 days before the race
-
Normal mixed diet
7 days before the race
-
Prolonged extreme physical activity
6-3 days before the race
carbohydrate
-
Protein and fat diet; no
2 and 1 days before the race
-
Large carbohydrate intake
Athlete B Up to 5 days before race
-
Normal mixed diet
5 days before the race
-
Prolonged extreme physical activity
4-1 days before the race
-
Large carbohydrate intake
-
Normal mixed diet
-
Large carbohydrate intake
Athlete C Up to 4 days before the race
4-1 days before the race
Page 26
The graph below shows the effect of each of these dietary regimes on glycogen levels in
the athletes’ muscles
(a)
(i)
What is the immediate effect of extreme physical activity on the glycogen
content of muscles?
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Describe how this effect occurs.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(b)
(i)
Evaluate the three regimes as preparation for a marathon race.
...........................................................................................................................
Page 27
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(ii)
Suggest a possible explanation for the different effects of the three regimes.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 9 marks)
Q22.
The diagram below shows a food web for some of the organisms which live in a
pond.
(a)
(i)
Name one secondary consumer in this food web.
...........................................................................................................................
(1)
Page 28
(ii)
The algae are small green plants.
Give three conditions needed by green plants to produce sugars.
1 ........................................................................................................................
2 ........................................................................................................................
3 ........................................................................................................................
(3)
(b)
This is a pyramid of biomass for the organisms in the aquarium.
Some of the biomass of the producers is not transferred to the tertiary consumers.
Explain, as fully as you can, what happens to this biomass.
(6)
(Total 10 marks)
Q23.
The graph below shows the effect of a high carbohydrate diet on the stored
carbohydrate in the muscles.
Page 29
Diet A
Diet B
Diet C
–
–
–
High carbohydrate diet, started after several days of eating a
diet without carbohydrate.
High carbohydrate diet, started after normal mixed diet.
Normal mixed diet.
What advice would you give the athlete about the best diet preparation for a long race?
Explain why you would give this advice.
Diet ......................................................................
Explanation
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 2 marks)
Page 30
Q24.
(a)
Put a tick ( ) in the correct boxes in the table below to show which of the
parts given are present in the cells and organisms listed.
CYTOPLASM
NUCLEUS
CELL WALL
GENES
Leaf mesophyll cell
Sperm
(2)
(b)
(i)
What is the main job of a leaf mesophyll cell?
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Explain one way in which the structure of the leaf mesophyll cell helps it to
carry out its job.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 5 marks)
Q25.
(a)
Put a tick ( ) in the correct boxes in the table below to show which of the
parts given are present in the cells and organisms listed.
CYTOPLASM
Leaf mesophyll cell
Sperm
Page 31
NUCLEUS
CELL WALL
GENES
(2)
(b)
(i)
What is the main job of a leaf mesophyll cell?
..................................................................................................................
..................................................................................................................
(1)
(ii)
Explain one way in which the structure of the leaf mesophyll cell helps it to
carry out its job.
..................................................................................................................
..................................................................................................................
..................................................................................................................
..................................................................................................................
(2)
(Total 5 marks)
Q26.
This is a diagram of a belt transect showing the major types of plants growing on the
bottom of a lake.
(a)
Suggest, and explain, two reasons why a much smaller population of Nitella plants
is found amongst the Potamogeton plants than further down in the lake.
1. ................................................................................................................................
Page 32
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
2. ................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(4)
(b)
Describe how you would use the belt transect technique to measure the abundance
and distribution of plants which live on the bottom of a shallow lake.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(3)
(Total 7 marks)
Q27.
Flightless birds called Rails once inhabited 20 islands in the Pacific Ocean. During
the last two centuries they have disappeared from 15 of these islands. The Aldabra Rail,
shown below, is one of the few survivors. The island which it lives on is very remote.
Page 33
Suggest three reasons why Rails have disappeared from 15 of the 20 islands they
once inhabited.
1. ..........................................................................................................................................
...............................................................................................................................................
2. ..........................................................................................................................................
...............................................................................................................................................
3. ..........................................................................................................................................
...............................................................................................................................................
(Total 3 marks)
Q28.
A plant with variegated (two-coloured) leaves was left in sunlight for several
hours. Pieces of one of its leaves were then detached (removed) and tested for
sugar. The diagram below shows the results.
Explain, as fully as you can, why the yellow region of the leaf had not produced sugar.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
Page 34
...............................................................................................................................................
...............................................................................................................................................
(Total 2 marks)
Q29.
The drawings below show a mammoth, an extinct relation of the elephant which
lived in arctic regions, and a modern elephant which lives in tropical areas.
The mammoth, which was very hairy, and the elephant, are both thought to have evolved
from a scantily haired ancestor. Explain, as fully as you can, how the mammoth evolved
from the common ancestor.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 5 marks)
##
Page 35
The passage below is an extract from an article in The Independent newspaper.
This Mouthwash could mean
a lot to your Children
A SIMPLE TEST SCREENS WOULD-BE PARENTS FOR THE
DEFECTIVE GENE THAT CAUSES
CYSTIC FIBROSIS
It is not every week that a university professor tells you to spit in front of him. But Bob Williamson,
professor of biochemistry and molecular genetics asked me to do just that.
In future, some people may choose their marriage partners on the basis of the contents of their spit.
The professor handed me a sample bottle containing sterile salt solution.
I rinsed my mouth out and spat back into the tube. Incredible though it may sound, the mouthwash
now contained enough cells from the inner lining of my cheek for an assistant to dissect my DNA and
check whether I carry any of the mutations responsible for cystic fibrosis.
Professor Williamson’s team can locate genetic markers, distinctive segments of DNA, that are
inherited along with the mutant genes in people affected with cistic fibrosis.
About 16 000 people who bought The Independent this morning unwittingly carry a cystic fibrosis
gene. The statistics indicate that 23 of the staff of this newspaper are unknowing carriers. Carriers are
normal healthy individuals who do not have the disease.
(a)
Describe, as fully as you can, where genes are located inside cheek cells.
.....................................................................................................................................
.....................................................................................................................................
(2)
(b)
The gene for cystic fibrosis has two forms called alleles. Only the recessive allele
causes cystic fibrosis.
Explain how two healthy carriers of the cystic fibrosis allele could produce a child with the
disease. Use the symbol A for the normal allele of the gene and a for the allele which
produces the disease. You may use a diagram if you wish.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 36
(4)
(d)
In the test used to identify the ‘genetic markers’, DNA is extracted from the cheek
cells. The DNA molecules are then made to produce hundreds of millions of copies
of themselves.
(i)
Explain, as fully as you can, how the structure of DNA molecules allows them
to replicate themselves.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(6)
(ii)
Explain how DNA controls the structure of proteins.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(Total 15 marks)
Page 37
Q31.
(a)
During respiration, sugar is oxidised to release energy. Complete the
equation for respiration.
Sugar + ............................. = ............................. + ............................. + energy
(3)
(b)
The photograph below shows an athlete using an exercise machine. The machine
can be adjusted to vary the rate at which the athlete is required to work.
The athlete’s heart rate and breathing rate were measured at different work rates.
The table below shows the results which were obtained.
WORK RATE
(J/s)
HEART RATE
(beats/min.)
BREATHING RATE
(breaths/min.)
0
86
9.6
60
106
10.0
80
112
10.4
100
122
10.4
120
135
11.4
140
143
14.5
160
156
15.8
200
174
30.5
Page 38
Plot the data on the graph paper below.
(3)
(c)
Explain, as fully as you can, the advantages to the body in the change in breathing
and heart rates.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 39
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(6)
(d)
This increase in the rate of heart-beat is a response to a stimulus. For this response
suggest:
(i)
the stimulus;
..........................................................................................
(ii)
the co-ordinator;
..........................................................................................
(iii)
the effector.
..........................................................................................
(3)
(Total 15 marks)
Q32.
Person A and Person B measured their pulse rates over a period of five minutes.
For one minute of this time they exercised by stepping on and off a box. At other times
they sat still. The graph shows the results for Person A.
Page 40
(i)
What does the graph tell you about the changes in the pulse rate of Person A
within the five minute period?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(ii)
What was the pulse rate of Person A at the end of the five minute period?
.....................................................................................................................................
(1)
(iii)
The table shows the results obtained for Person B.
Time
in minutes
Pulse rate per minute
0
68
Page 41
1
68
2
110
3
96
4
80
5
68
Plot these results on the graph.
(2)
(Total 6 marks)
Q33.
In humans, the sex chromosomes X and Y determine whether the baby will be male
or female (its gender).
(a)
(i)
Draw a genetic diagram to show how gender is inherited. The male has XY
chromosomes and the female has XX.
(2)
(ii)
What is the likelihood of obtaining a male child?
.........................................................................................................................
(1)
(b)
In the 16th century Henry VIII was the King of England. He blamed some of his
wives for giving birth to daughters instead of sons. With our present day knowledge
of genetics this mistake could not be made today. Explain why Henry VIII was
wrong.
....................................................................................................................................
....................................................................................................................................
Page 42
....................................................................................................................................
(2)
(Total 5 marks)
Q34.
The drawing shows an animal cell, seen at a very high magnification using an
electron microscope.
(a)
(i)
Label a mitochondrion [plural = mitochondria].
(1)
(ii)
What happens in the mitochondria?
..........................................................................................................................
(1)
(b)
(i)
Name and label the structure where you would find chromosomes.
(1)
Page 43
(ii)
What are chromosomes made of?
..........................................................................................................................
(1)
(c)
What controls the rate of chemical reactions in the cytoplasm?
....................................................................................................................................
(1)
(Total 5 marks)
Q35.
Photosynthesis takes place the leaves of green plants.
(a)
Write a balanced chemical equation for the formation of glucose by photosynthesis.
....................................................................................................................................
(3)
(b)
Describe two ways that the rate of photosynthesis can be decreased without
lowering the temperature.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(c)
Some students decided to investigate 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. The counted the number of bubbles given off
in a minute at different temperatures. They obtained the following results.
Page 44
(i)
Plot the points on the graph.
(3)
(ii)
Use your graph to predict the number of bubbles per minute at 25 °C.
..........................................................................................................................
(1)
(iii)
Suggest a reason why the rate of photosynthesis seems to decrease in this
pondweed after 40 °C.
Page 45
..........................................................................................................................
..........................................................................................................................
(1)
(Total 10 marks)
Q36.
(a)
The diagram shows a normal body cell which has six chromosomes.
(i)
Complete the diagram below to show one cell produced from this cell by
mitosis.
(3)
(ii)
Complete the diagram below to show one cell produced from the original cell
by meiosis.
Page 46
(2)
(b)
Thalassaemia is a blood disease. It is determined by a single recessive allele. A
person with one recessive allele does not get the disease but does act as a carrier.
People with this pair of recessive alleles can become ill.
(i)
Draw a genetic diagram to show the inheritance of' this disease if both parents
are heterozygous.
[Use the symbols T = dominant allele and t = recessive allele]
(3)
(ii)
What are the chances of a baby inheriting the disease?
..........................................................................................................................
(1)
(iii)
What are the chances of a baby being a carrier if both parents are
heterozygous?
..........................................................................................................................
(1)
(Total 10 marks)
Page 47
Q37.
The diagram shows how a leaf of a green plant makes glucose.
(a)
Use words from the box to complete the labels on the diagram. You may use each
word once or not at all.
carbon dioxide
chlorophyll
light
oxygen
glucose
heat
water
(5)
(b)
(i)
Compete the following sentence.
Glucose in food is a type of ................... . When we eat it, it gives us energy.
(1)
Page 48
(ii)
The plant turns some of the glucose into starch. Why is starch useful to the
plant?
..........................................................................................................................
..........................................................................................................................
(1)
(iii)
What does the plant do with the rest of the glucose?
..........................................................................................................................
(1)
(c)
(i)
What is the name of the process outlined in the diagram?
..........................................................................................................................
(1)
(ii)
Give one way that leaves are adapted to do this process.
..........................................................................................................................
(1)
(Total 10 marks)
Q38.
(a)
Photosynthesis is a process that takes place in green plants.
(i)
What type of energy is needed for this process?
..........................................................................................................................
(1)
(ii)
What substance in the plant absorbs this energy?
..........................................................................................................................
(1)
Page 49
(iii)
In which part of the plant cell does photosynthesis take place?
..........................................................................................................................
(1)
(iv)
Write a balanced chemical equation for photosynthesis.
......................................................... → ..........................................................
(3)
(b)
Describe two ways you could speed up photosynthesis.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
The diagram shows the outline of a cross-section of a leaf. Name cells 1 and 2 and
describe how they are involved in photosynthesis.
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
...................................................................................
(4)
(Total 12 marks)
Page 50
Q39.
The diagram shows a human sperm. Inside the tail of the sperm is a filament
mechanism that causes the side to side movement of the tail, which moves the sperm.
(a)
Describe the function of the mitochondria and suggest a reason why they are
arranged around the filament near the tail of the sperm.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(b)
Explain the significance of the nucleus in determining the characteristics of the
offspring.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 5 marks)
##
(a)
Complete the table to give one site where digestive substances are made.
Digestive substance
One site of production
Page 51
bile
amylase
lipase
protease
(4)
(b)
Describe two ways that the mouth can break down starchy foods.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
Describe how the liver helps to digest fats.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 8 marks)
Q41.
The chromosomes for determining the gender or sex of a person are labelled X and
Y.
Page 52
(a)
Complete the Punnett Square to show the genotype of parent 2 and of the four
offspring.
(3)
(b)
Which parent is the mother?
.....................................................................................................................................
(1)
(c)
What are the chances of getting a baby boy?
.....................................................................................................................................
(1)
(Total 5 marks)
Q42.
(a)
Plants make their own food by photosynthesis.
Page 53
Use the following words to fill in the gaps. You can use each word once or not at
all.
carbon
chlorophyll
oxygen
cytoplasm
sound
starch
light
nitrogen
water
During photosynthesis .............................................. dioxide and .............................
are converted into glucose and ........................................ . The energy needed to do
this is ......................................... energy which is trapped by a green pigment called
......................................... .
The plant can change the glucose into ..................................... which is insoluble so
it can be stored.
(6)
(b)
Which part of a plant is adapted for photosynthesis?
....................................................................................................................................
(1)
(c)
How do the two raw materials for photosynthesis get into the plant?
1. ...............................................................................................................................
....................................................................................................................................
Page 54
2. ................................................................................................................................
....................................................................................................................................
(2)
(d)
Describe one way you could speed up photosynthesis.
....................................................................................................................................
.....................................................................................................................................
(1)
(Total 10 marks)
Q43.
Meiosis and mitosis are different types of division in human cells. Compare the two
processes by referring to where each takes place and the kind of products that are made.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 6 marks)
Page 55
Q44.
In the 1850s an Austrian monk, called Gregor Mendel, carried out a series of
investigations on heredity.
(i)
What plants did he use for his investigations?
....................................................................................................................................
(1)
(ii)
In his work he assumed that one gene controlled one characteristic. He started his
investigations with pure breeding parents. Use a genetic diagram to show how he
explained the following result.
(4)
(Total 5 marks)
Q45.
(a)
The volume of blood pumped out of the left ventricle at each beat was
measured for a person during six different activities. These activities showed an
increasing energy demand, with rest requiring the least energy and rowing a boat
the most. The results of these measurements are shown on the bar chart.
Page 56
(i)
The pulse rate was also measured for the person during the same activities.
The table shows the results that were obtained.
Activity
Pulse rate in
beats per minute
Rest
70
Writing
85
Cleaning the floor
100
Wallpapering
120
Walking fast
132
Rowing a boat
153
On the graph paper below draw a bar chart of the results obtained for the
measurements of the pulse rate.
Page 57
(2)
(ii)
Undertaking activities with increasing energy demand has an effect on the
volume of blood pumped from the left ventricle (per beat) and on the pulse
rate. What do the bar charts show these effects to be? Use only information
shown in the bar charts in your answer.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(b)
The pulse rate changed when the activity changed. Explain the reason for this.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(Total 6 marks)
Page 58
Q46.
(a)
Complete the following sentences.
Green plants produce their own food by a process called photosynthesis. In this
process the raw materials are ...................................................... and carbon
dioxide. Glucose and ............................................................... are produced.
.................................................... energy is absorbed by the green substance
called .................................................... .
(4)
(b)
Name two things that can happen in the plant to the glucose produced in
photosynthesis.
1. ..............................................................................................................................
2. ...............................................................................................................................
(2)
(c)
Plants need mineral salts.
(i)
Through which part do mineral salts get into the plant?
...........................................................................................................................
(1)
(ii)
Explain why water is important in this process.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
Some students set up water cultures to find out how plants use nitrates.
They had two sets of nutrient solutions.
A full solution provided the plant with all the required nutrients.
Page 59
The results table shows the average mass of the seedlings after 28 days of growth.
(d)
(i)
Give a conclusion you could make from these results.
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Calculate the difference in average mass caused by the addition of nitrates to
the culture solution.
...........................................................................................................................
(1)
(iii)
What are nitrates used for in the seedling?
...........................................................................................................................
(1)
(iv)
Some factors need to be controlled to keep this test fair. Name two of them.
1. .....................................................................................................................
2. ....................................................................................................................
(2)
Page 60
(v)
Suggest one way you could improve the experiment.
...........................................................................................................................
(1)
(Total 15 marks)
Q47.
(a)
Mice with black fur can have the genotype BB or Bb, whilst mice with brown
fur have the genotype bb.
(i)
Use a genetic diagram to show what fur colours you would predict in the F1
offspring produced by two mice who are both Bb.
(3)
(ii)
Why might your prediction of fur colour in the F1 generation not be proved
right?
...........................................................................................................................
...........................................................................................................................
(1)
(b)
Using the example in part (a) to help:
(i)
describe the difference between dominant and recessive alleles;
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
Page 61
...........................................................................................................................
(2)
(ii)
describe the difference between alleles and genes;
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(iii)
describe the difference between homozygous and heterozygous
chromosomes.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 10 marks)
Q48.
The black pigment in human skin and eyes is called melanin. Production of melanin
is controlled by a single pair of genes. A person who is homozygous for a recessive allele
of the gene has no melanin and is said to be albino.
(a)
A man is albino. His wife is heterozygous for the melanin-producing allele.
(i)
The fertilised egg cell produced by the couple divides to form two cells.
Name the process of cell division involved.
..........................................................................................................................
(1)
(ii)
How many albino genes would there be in each of these two cells?
Page 62
..........................................................................................................................
Explain you answer.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(3)
(b)
(i)
Albino people are more likely than people with melanin to suffer mutations
that cause cancer in their skin. Suggest why albino people have an increased
chance of mutation in their skin cells.
..........................................................................................................................
..........................................................................................................................
(1)
(ii)
Sometimes, mutation in skin cells leads to cancers in other organs, such as
the liver.
Explain how.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(Total 7 marks)
Q49.
The graph shows the effect of increasing the carbon dioxide content of the inhaled
air on:
•
the number of breaths per minute;
•
the total volume of air breathed per minute.
Page 63
(i)
Describe the effect of increasing the percentage of carbon dioxide in the inhaled air
on the total volume of air breathed.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(ii)
Suggest why the total volume of inhaled air is not directly proportional to the
number of breaths per minute.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 4 marks)
Page 64
Q50.
(a)
Use words from the list to complete the sentences.
alleles
chromosomes
gametes
genes
mutations
The nucleus of a cell contains thread-like structures called ..................................... .
The characteristics of a person are controlled by .....................................
which may exist in different forms called ..................................... .
(3)
(b)
The drawing shows some of the stages of reproduction in horses.
(i)
Name this type of reproduction .......................................................................
(1)
(ii)
Name the type of cell labelled A .....................................................................
(1)
Page 65
(c)
When the foal grows up it will look similar to its parents but it will not be identical to
either parent.
(i)
Explain why it will look similar to its parents.
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Explain why it will not be identical to either of its parents.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 8 marks)
Q51.
The drawing shows part of a root hair cell.
(a)
Use words from the list to label the parts of the root hair cell.
cell membrane
cell wall
cytoplasm
Page 66
nucleus
vacuole
(4)
(b)
The diagram shows four ways in which molecules may move into and out of a cell.
The dots show the concentration of molecules.
The cell is respiring aerobically.
Which arrow, A, B, C or D represents:
(i)
movement of oxygen molecules;
(ii)
movement of carbon dioxide molecules?
....................
....................
(2)
(c)
Name the process by which these gases move into and out of the cell.
.....................................................................................................................................
(1)
(Total 7 marks)
Q52.
This couple has just found out that the woman is pregnant. They wonder whether
the child will be a boy or a girl.
Page 67
(a)
Fill in the boxes to show the sex chromosomes of the woman and the man.
(2)
(b)
The couple already has one girl. What is the chance that the new baby will be
another girl?
.....................................................................................................................................
Explain the reason for your answer. You may use a genetic diagram if you wish.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 68
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 5 marks)
Q53.
The diagram shows a plant leaf during photosynthesis.
(a)
Name:
(i)
gas X;
..............................
(ii)
gas Y.
..............................
(2)
(b)
Why is sunlight necessary for photosynthesis?
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 3 marks)
Page 69
Q54.
The drawing shows some of the stages of reproduction in horses.
(a)
(i)
Name this type of reproduction .......................................................................
(ii)
Name the type of cell labelled A .....................................................................
(1)
(1)
(b)
Name the type of cell division taking place at the stage labelled:
(i)
B ......................................................................................................................
(ii)
C ......................................................................................................................
Page 70
(2)
(c)
How does the number of chromosomes in each cell of the embryo compare with the
number of chromosomes in cell A?
.....................................................................................................................................
(1)
(d)
When the foal grows up it will look similar to its parents but it will not be identical to
either parent.
(i)
Explain why it will look similar to its parents.
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Explain why it will not be identical to either of its parents.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 8 marks)
Q55.
Describe the roles of the liver and the pancreas in the digestion of fats.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
Page 71
...............................................................................................................................................
...............................................................................................................................................
(Total 5 marks)
Q56.
The diagram shows a plant leaf during photosynthesis.
(a)
Name:
(i)
gas X; ..............................
(ii)
gas Y. ..............................
(2)
(b)
Why is sunlight necessary for photosynthesis?
.....................................................................................................................................
.....................................................................................................................................
(1)
Page 72
(c)
Some of the sugars produced by photosynthesis are stored as starch in the roots.
Explain, as fully as you can, why it is an advantage to the plant to store
carbohydrate as starch rather than as sugar.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 6 marks)
Q57.
The drawings show bolls on cotton plants. Cotton thread is made from these bolls.
The size of the bolls is controlled by a single gene. This gene has two alleles. The
dominant allele B is the allele for large bolls. The recessive allele b is the allele for small
bolls.
Use a genetic diagram to show how two cotton plants with large bolls may produce a
cotton plant with small bolls.
Page 73
(Total 4 marks)
##
Read the passage.
Designer Denim Genes
USA scientists have successfully used genetic engineering to insert genes for blue pigment into cotton plants.
Their aim is to get cotton plants which produce blue cotton so that denims can be manufactured without the
need for dyeing. The scientists have also inserted genes that prevent cotton fibres twisting, with the aim of
producing drip dry shirts made from natural fibres. Other cotton plants are being genetically engineered to
produce their own insecticides. When they have perfected these new types of cotton plants, the scientists will
use cloning techniques to produce large numbers of them.
(i)
Name the substance in cells which carries genetic information.
.....................................................................................................................................
(1)
(ii)
Explain how molecules of this substance control characteristics such as blue colour
in cotton plants.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 4 marks)
Page 74
Page 75
M1.
(a)
digested / broken down / made soluble by protease enzyme
in stomach in small intestine / from stomach / from pancreas
into amino acids
amino acids / small molecules absorbed into blood
any four for 1 mark each
4
(b)
ideas that
lipase / enzyme works best in alkaline / neutral conditions
acid denatures or inactivates enzyme / inhibits enzyme activity
bile emulsifies fat / bile produces larger surface area of fats / bile alkaline
for enzyme to work on / which increase activity of enzymes
any three for 1 mark each
3
[7]
M2.
(a)
21.5 – 22 and 27 – 27.5
for 1 mark
1
(b)
ideas of
limiting factor / shortage of
e.g. light / carbon dioxide / water / chlorophyll
each for 1 mark
(allow 1 for ‘maximum / optimum rate of enzyme activity if no
reference to limiting factors) (ignore denaturation)
2
(c)
21.5 – 22° C
(allow first figure from answer to (i) so that no
‘double-penalty but only if this first answer is 20 or greater)
maximum rate of photosynthesis / highest / fastest
but related to flat part of curve
most economical heating / cheapest related to heating
Page 76
must relate to the temperature the candidate has given
each for 1 mark
3
[6]
M3.
cytoplasm reject protoplasm
(cell) membrane
nucleus
all correctly labelled
each for 1 mark
[3]
M4.
(a)
Sun / sunlight / light
for 1 mark
1
(b)
(i)
21.5 – 22 and 27 – 27.5
for 1 mark
1
(ii)
ideas of limiting factor / shortage of
e.g. light / carbon dioxide / water /chlorophyll
each for 1 mark
(allow 1 for ‘maximum’ rate of enzyme activity if
no reference to limiting factors)
(ignore reference to dematuring)
2
(iii)
21.5 – 22° C
(allow first figure from answer to (i) so that no
‘double-penalty’ but not below 20)
Page 77
maximum rate of photosynthesis
(can relate to any number on ‘flat’)
most economical heating (must relate to left end of ‘flat’
each for 1 mark
3
[7]
M5.
(a)
10
for 1 mark
1
(b)
digested / broken down / made soluble by protease / enzyme
in stomach / in small intestine / from stomach / from pancreas
into amino acids amino acids/smaller molecules/products of digestion absorbed into
blood
any four for 1 mark each
4
[5]
M6.
D
idea that twins have come from one (fertilised) egg
idea that Y sperm / Y chromosome produces boys
each for 1 mark
allow 1 mark if candidate selects A and states that Y sperm /
Y chromosome produce boys (reject Y gene unqualified) OR
allow 1 mark if candidate selects C and states that twins
must have come from one (fertilised) egg
[3]
Page 78
M7.
(a)
(i)
D
for 1 mark
1
(ii)
D
Y (both) or C X (both) or B W (both)
for 1 mark
1
(b)
N.B. answers must relate to fossils providing evidence
show types of animals / plants that no longer exist / named ref eg dinosaur
show changes in types (of animals / plants)
similar fossils found in rocks of similar age
reference to sequence of change
or example
e.g. horse / limb
any two for 1 mark each
2
[4]
M8.
(i)
cytoplasm
(cell) membrane
nucleus
all correctly labelled
each for 1 mark
3
(ii)
0.5
gains 2 marks
(5/100 × 10 or ½ /1 gains 1 mark if 0.5 not given)
2
[5]
M9.
(i)
DNA
Page 79
for 1 mark
1
(ii)
contains the code for manufacturing the protein,
as order of bases,
which determine the order in which amino acids are
assembled into protein
for 1 mark each
3
[4]
##
(a)
mutation
for 1 mark
1
(b)
fall,
idea that resistant beetles more likely to survive to breed,
their offspring more likely to appear in the next generation
for 1 mark each
3
(c)
inbreeding between resistant brothers and sister,
will produce some individuals with 2 copies of the resistance allele,
if 2 of these individuals breed all their offspring will be resistant
for 1 mark each
3
[7]
M11.
(i)
the higher the rate of oxygen consumption, the shorter the
time taken to complete
for 1 mark
1
Page 80
(ii)
the faster oxygen is taken into the blood,
the faster energy can be released in the muscles,
and the faster the athlete can run
for 1 mark each
3
[4]
M12.
genotype of parent A Nn
gametes N n n n
young genotypes and phenotypes all correct
for 1 mark each
[3]
##
(a)
oxygen,
carbon dioxide or water (vapour)
for 1 mark each
2
(b)
idea of more air per breath/deeper breaths
for 1 mark
1
(c)
(i)
respiration
for 1 mark
1
(ii)
carbon dioxide,
water
for 1 mark each
2
Page 81
(iii)
more energy required,
for increased muscular activity
for 1 mark each
2
[8]
M14.
(a)
(i)
280 million years
for 1 mark
1
(ii)
e.g. the climate changed
for 1 mark
1
(iii)
e.g. the desert climate in the Permian was too dry for them
for 1 mark
1
(b)
replaced by other materials/hard parts did not decay/
exclusion of oxygen prevents decay
for 1 mark
1
[4]
M15.
(a)
(i)
e.g. B and b
for 1 mark
1
(ii)
e.g. bb
for 1 mark
1
Page 82
(b)
no black genes in flock
all double recessive
for 1 mark each
2
[4]
M16.
(a)
(i)
June
for 1 mark
1
(ii)
April
max. light
photosynthesis makes sugars/substances needed for growth
for 1 mark each
3
(b)
2 of:
temperature
carbon dioxide availability
water
chlorophyll
any 2 for 1 mark each
2
[6]
M17.
(a)
(i)
bones [and feathers]
1
for 1 mark
(ii)
hard parts do not decay
for 1 mark each
2
(iii)
has feathers
for 1 mark
Page 83
1
(b)
(i)
all of kind have died out
for 1 mark
1
(ii)
e.g. change of habitat
for 1 mark
1
(iii)
named extinct organism, e.g. Dinosaur
1
for 1 mark
[7]
M18.
(a)
Stan BB
Sharon bb
all offspring Bb
3
(b)
Tom Bb
black offspring Bb
white offspring bb
3
[6]
M19.
(a)
carbon dioxide
oxygen
2
(b)
(i)
e.g. rubber plant/fern
1
Page 84
(ii)
because can tolerate low light levels
1
(iii)
yellow parts of leaf do not contain chlorophyll therefore more light
needed for photosynthesis
2
(iv)
no leaves/only have stem only have small area which can
photosynthesise
2
[8]
M20.
Cogently argued based on biological principles, for and
against experimenting with human fertilisation techniques
max 4 pros e.g.
help for women who cannot conceive naturally
possibility of eliminating disease causing genes
possibility of inserting useful animal genes
max 4 cons e.g.
ethical objections
religious objections
social issues
any 6 for 1 mark each
6
cogently argued case gains up to 2 marks
2
[8]
M21.
(a)
(i)
reduced sharply
for 1 mark
1
(ii)
converted to glucose which is respired to produce energy
(allow answers in terms of glucagon)
Page 85
gains 3 marks
3
(b)
(i)
athlete A’s was most effective
since resulted in highest muscle glycogen level on day of race
for energy release during race
for 1 mark each
3
(ii)
e.g. excess carbohydrate stored as glycogen rather than fat in short term
particularly if glycogen stores depleted
for 1 mark each
2
[9]
M22.
(a)
(i)
e.g. mussels/caddis loach
for 1 mark
1
(ii)
3 of:
carbon dioxide
water
chlorophyll/chloroplasts
light
any 3 for 1 mark each
3
(b)
6 of e.g.
some plant/animal material not digested by consumers passes out with faeces
respiration releases energy used in movement lost as heat
some ‘lower’ organisms die energy transferred to decomposers/detritivores
thence to environment
any 6 for 1 mark each
6
[10]
Page 86
M23.
follow diet A because it gives the highest proportion of stored sugar in the muscles
for 1 mark each
[2]
M24.
(a)
mesophyll / / / / (all correct)
sperm
/ / x / (all correct)
for 1 mark each
2
(b)
(i)
absorbs light/to produce food
(allow reference to gaseous exchange)
for 1 mark
1
(ii)
e.g.
has chlorophyll/chloroplasts
has elongated shape to absorb light
for 1 mark each
2
[5]
M25.
(a)
mesophyll / / / / (all correct) sperm / / x / (all correct)
for 1 mark each
2
Page 87
(b)
(i)
absorbs light/to produce food/photosynthesis
(allow references to gaseous exchange)
for 1 mark
1
(ii)
has chlorophyll/chloroplasts to absorb light/produce food
for 1 mark each
(if linked to gas exchange allow – moist surface/
dissolve gases)
2
[5]
M26.
(a)
e.g.:
competition for light because potamogeton plants taller
competition for nutrients taller plants may have longer roots
each for 1 mark
4
(b)
descriptions of:
measuring tape or similar quadrat
method of estimating cover (inside quadrat)
each for 1 mark
3
[7]
M27.
3 of e.g.
new predators
new diseases
new competitors
environmental changes (initiated by Man)
each for 1 mark
[3]
Page 88
M28.
Does not contain chlorophyll which is needed to absorb light or energy
each for 1 mark
[2]
M29.
natural variation in amount of body hair;
in cold environment, (having genes) which produce long hair is an advantage;
because hair insulates; OWTTE
such animals more likely to survive;
and pass these genes onto succeeding generations
each for 1 mark
[5]
M30.
(a)
on chromosomes/DNA within the nucleus
each for 1 mark
2
(b)
parental genotypes correct i.e. Aa Aa;
gamete genotypes correct i.e. A or a A or a/correct lines;
F1 genotypes correct i.e.
AA Aa Aa aa;
aa recognised as child with cystic fibrosis
each for 1 mark
4
(d)
(i)
molecule has two long strands/double helix;
idea of held together by (weak) bonds;
each strand has 4 different types of base;
which pair with specific bases in opposite strand;
Page 89
)
)
when strands separate;
each strand acts as a ‘complementary’ template;
makes 2 identical strands
each for 1 mark
) OWTTE
)
)
6
(ii)
order of bases acts as a code;
which controls the order;
in which amino acids are assembled into protein;
read in triplet
each for 1 mark
3
[15]
M31.
(a)
oxygen;
)
carbon dioxide; ) allow symbols
water
)
each for 1 mark
3
(b)
graph with reasonable vertical scales;
accurate plotting of all points (ignore lines) and labelling lines
histogram – must be coded
gains 3 marks
3
(c)
6 of:
during exercise the level of CO2 (in the blood) rises;
increased breathing to remove excess CO2;
increased oxygen supply to muscles;
or increased breathing takes in more O2
or increased heart rate takes more O2 to muscles;
increased supply of sugar to muscles;
increased respiration rate;
enable faster rate of energy release;
reference to lactic acid (allow even though not on syllabus)/O2 debt;
to avoid cramp;
anaerobic reference;
reference to removal of ‘heat’;
6
Page 90
(d)
high carbon dioxide concentration;
brain/central nervous system;
heart muscles (both)
3
[15]
M32.
(i)
with exercise rate rises;
accept between 1 – 2 minutes rate rises
1
(when exercise stops) rate falls slowly;
accept gentle fall or steady fall
for answers which just describe a rise then a fall allow one
mark only as an alternative to the first two points
1
rate does not return to normal or to starting or to resting rate
accept rate returns to normal after five minutes or three
minutes of rest or after recording ended
1
(ii)
86 (per minute);
1
(iii)
plotting points;
deduct one mark for each error to max of two
if 68 wrongly plotted count as one error (ignore the quality of
the line)
Page 91
2
[6]
M33.
(a)
(i)
gametes correct
allow by implication from line diagram
only need on X from female
1
offspring genotype correctly derived
on suitable diagram
or
1
(ii)
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)
Page 92
1
(b)
Y chromosome needed for male child
1
only male has the Y or wives had only X (chromosomes)
or sex determined by the sperm
1
[5]
M34.
(a)
(i)
award 1 mark for any of the mitochondria correctly labelled if
a number are labelled and one is incorrect award 0 marks
1
(ii)
respiration or the release or transfer
of energy or it contains the enzymes
for respiration
do not accept energy produced
1
(b)
(i)
nucleus (named and correctly
labelled)
Page 93
arrow or line must touch or go inside the nuclear membrane
1
(ii)
DNA or genes or nucleic acids
accept protein or histones or nucleotides or ATGC
1
(c)
enzymes or nucleus
do not accept factors that affect the rate rather than control it
eg pH or temperature
1
[5]
M35.
(a)
reactants: CO2 + H2O
1
products: C6H12O6 + O2
1
balance:
6CO2 + 6H2O → C6H12O6 + 6O2
1
(b)
1 mark each for any of the following
ideas:
lower CO2 concentration
Page 94
lower light intensity
decrease water availability
alter light wavelength or colour
accept more green light
2
(c)
(i)
scales correctly constructed
i.e. equal intervals along each axis
1
points plotted correctly
1
appropriate line correctly drawn
accept dot to dot or line of best fit
cancel if line extends through zero or beyond 50°C
1
(ii)
18 – 19 (bubbles per minute)
1
(iii)
heat denatures enzymes or destroys
membranes or ruptures cells or
destroys cells
do not accept kills enzymes
1
[10]
##
(a)
(i)
if two nuclei drawn then maximum two marks
1
6 chromosomes
1
same 3 homologous pairs
1
nuclear membrane drawn
1
Page 95
(ii)
3 chromosomes
1
1 from each homologous pair
1
(b)
(i)
parent line must be separate
heterozygous parents Tt × Tt
maximum of 2 marks if parental genotype is wrong
gametes correct T t T t
1
genotypes TT Tt Tt tt
1
(ii)
correct analysis of chance i.e. 1 in 4
or 25%
1
(iii)
50% or 1 in 2
1
[10]
M37.
(a)
Page 96
5
(b)
(i)
sugar or carbohydrate
1
(ii)
it can be stored or it is insoluble
accept it has no osmotic effect
1
(iii)
any one from:
respires it or releases or transfers
energy
turns it or stores it as fructose or
sucrose or lipid or protein or
cellulose
1
(c)
(i)
photosynthesis
1
(ii)
any one from:
flat surface
stomata
thin
chloroplasts
veins
large surface area
air spaces
do not accept chlorophyll
1
[10]
Page 97
M38.
(a)
(i)
light or solar
do not credit sun’s energy
do not credit radiant
1
(ii)
chlorophyll
1
(iii)
chloroplast
1
(iv)
CO2 + H2O
reactants identified (accept words)
1
C6H12O6 + O2
products identified (accept words)
1
6CO2 + 6H2O → C6H12O6 + 6O2
balanced equation
1
(b)
any two from:
increased CO2 concentration
increased water supply
increased temperature (up to a point)
increased light intensity
do not accept heat or warmth
altered light quality by less green or
increasing other colours
2
(c)
any four points
•
palisade (mesophyll)
Page 98
•
lots of chloroplasts or chlorophyll
or main site for photosynthesis
or absorb maximum amount of light
•
guard cells
•
CO2 in or O2 out or water vapour
out
•
controls size of stoma or pores in
leaf
allow stomata
4
[12]
M39.
(a)
award one mark for each key idea
energy released or energy transferred or respiration
allow provides or gives
do not allow produces or makes
3
near to the site of movement or
energy available quickly or more
energy
accept allows more mitochondria to fit in
(mitochondria) packed (around
filament) or efficient arrangement or
spiral arrangement
(b)
contains chromosomes or genes or
DNA
not genetic material
1
(which) contribute half (the genes) to
the fetus or offspring
23 chromosomes or half the genes
Page 99
or reference to X,Y chromosome determining sex (if the
notion of halfness is there)
nucleus contains half genes for the offspring = 2 marks
1
[5]
M40.
(a)
liver
1
mouth or salivary glands or
duodenum or small intestine or
pancreas
1
pancreas
accept duodenum or ileum or
small intestine
do not accept stomach
1
stomach or duodenum or ileum or
small intestine or pancreas
1
(b)
teeth breakdown food
accept chewing
1
amylase or saliva (breaks down starch)
1
(c)
produces bile (salts)
1
emulsifies (fat) or produces droplets
or disperses fat)
1
[8]
Page 100
M41.
clearly labelled ‘y’
(a)
1
mark the offspring in two horizontal
rows
1 mark for each fully correct row
allow transferred error if parent 2 is incorrect
XX
XX
1
XY
XY
accept YX
1
(b)
parent 1
accept XX
1
(c)
50:50
or
equal or even
or
1:1 or 50%
accept 1/2 or 2/4
1
[5]
M42.
(a)
carbon
water
oxygen
light
chlorophyll
Page 101
starch
1 mark each
6
(b)
leaf (or named part of leaf)
or
chloroplasts
accept anywhere green
do not credit chlorophyll unless qualified
1
(c)
water through the roots
or
root hairs
or
by osmosis
do not credit where the candidate is unclear about which is
which
1
CO2 through the leaf
or
stomata
or
by diffusion
1
(d)
any one point:
increased CO2 concentration
increased water supply
increased temperature (up to a point)
increased light (intensity)
accept altered light quality by less green or increasing other
colours
accept increased duration of exposure to light
do not credit sun or sunshine
accept CO2 from respiration
1
[10]
Page 102
M43.
one mark for each of the following
comparisons to a maximum of 6
candidates must make a clear comparison
meiosis
mitosis
sexual
asexual
gametes
growth
ovary or testes
or gonads
all other cells
half number
of chromsomes
same number
of chromosomes
haploid or
23 chromosomes
diploid or
46 chromosomes
reassortment or
variation possible
or not identical
no reassortment
or no variation
or identical
4 cells produced
2 cells produced
2 divisions
1 division
[6]
M44.
(i)
(sweet) peas
1
(ii)
homozygous parents crossed [1]
heterozygous (F1) offspring crossed [1]
recognition of yellow dominant over green [1]
recognition that results support 3:1 or
0.75 to 0.25 ratio
up to 4 marks awarded for an understanding of the
monohybrid cross and the expected outcome
4
[5]
Page 103
M45.
(a)
(i)
plotting values for pulse rates;
2 marks- minus 1 mark for each error to a maximum of 2
Accept values if plotted on blood volume bar chart
Non-horizontal tops to bars producing variable values = 1
error
If drawn as a line graph =1 mark maximum
2
(ii)
Either
volume of blood went up then fell;
Accept went to a maximum then fell
Page 104
pulse rate increased (steadily);
Accept went up steadily or kept going up
2
Or
at first or with low activity or with moderate activity both pulse and
volume increased;
Accept activity up to wall- papering
with more activity pulse continued to increase but volume fell;
(b)
Any two of
with increased activity greater muscle use or greater respiration;
need more glucose or oxygen;
Accept more sugar
heart beat faster;
Do not accept more air
Accept more blood needed or blood flows faster
If ‘more’ or equivalent stated once it can be accepted
elsewhere by implication
2
[6]
M46.
(a)
water [1]
oxygen [1]
(sun) light or solar [1]
do not accept sun’s
chlorophyll [1]
do not accept chloroplasts
4
(b)
any two from:
Page 105
stored as fructose
stored as sucrose
stored as starch
stored as oil or lipid
moved or transported away in the phloem
do not accept “stored” by itself
respired or burnt up for energy or
fuel changed to protein
changed to cellulose
changed to fructose
changed to starch
changed to oil or lipid
do not accept “food for plant”
do not accept “used up” by itself
2
(c)
(i)
roots or root hair (cells)
1
(ii)
the mineral salts are (dissolved) in water [1]
water transports salts throughout the plant
or water enables osmosis or diffusion to take place [1]
2
(d)
(i)
plants grow better with some nutrients than none
or
plants grow better with nitrates than without
comparison is needed
accept “faster” as equivalent to “better”
accept don’t grow well with only water
1
(ii)
0.14(g)
units not needed
1
(iii)
making protein or amino acids
do not accept help them grow
accept named protein or DNA or chlorophyll
1
Page 106
any two from:
(iv)
type or variety or starting weight or
2
(iii)
size of seedlings
keep the environment the same
only if light or temperature or day
length not already credited
light
temperature not heat
time of growth
do not accept the same equipment
do not accept help them grow
1
day length
amount of culture solution or/size of
accept named protein, DNA chlorophyll
boiling tube
number of seedlings per tube
pH
CO2
humidity
[15]
M47.
(a)
(i)
gametes i.e. B b and B b
1
correct combination of genotypes i.e. BB, Bb, Bb, bb
1
correct analysis of phenotypes i.e. 3 black fur 1 with brown fur
1
(ii)
award one mark for the recognition
that it is down to chance (which two
gametes fuse) and not simply ‘because
it’s a prediction’
do not accept mutation
Page 107
1
(b)
(i)
B is dominant/ an allele is dominant if it is expressed in the heterozygous
phenotype
candidates are likely to use a variety of ways of expressing
their ideas
1
b is recessive/ a recessive allele is not expressed in the presence of its
contrasting allele
do not accept powerful
do not accept stronger
1
(ii)
alleles are different forms of a gene controlling a characteristic and
occupying the same site on homologous chromosomes (e.g. B or b)
1
genes are the units of DNA/sites on chromosomes carrying the information
that determines characteristics (e.g. bB)
1
(c)
homozygous: BB / bb / possessing a pair of identical alleles
for a character/true breeding
give credit to an explanation using a diagram
1
heterozygous: Bb / carrying a pair of contrasting/different alleles for a characteristic
do not accept references to xx, xy
do not accept gene by itself
1
[10]
M48.
(a)
(i)
mitosis
Page 108
for 1 mark
1
(ii)
1
fertilised egg cell has 1 albino gene from father splits to produce
identical cells / produced by mitosis
each for 1 mark
3
(b)
(i)
less protection from UV light / UV radiation
for 1 mark
1
(ii)
ideas of uncontrolled multiplication of mutated cells reject fast /
rapid cell division cells invade of other parts / cells transported in blood
each for 1 mark
2
[7]
M49.
(i)
increase in CO2 concentration leads to increase in volume of air inhaled
increase of % carbon dioxide has little effect over most of range / large
increase when % carbon dioxide > 5.6 %
each for 1 mark
2
(ii)
idea that
depth of breathing changes at low % carbon dioxide, in crease in % CO2
results in volume of each breath increasing without increase / little increase
in number of breaths
each for 1 mark
2
[4]
M50.
(a)
chromosomes
genes
(reject alleles)
Page 109
alleles
for 1 mark each
3
(b)
(i)
sexual / sex
for one mark
1
(ii)
egg / gamete / sex cell / ovum
for one mark
(reject ovule)
1
(c)
(i)
information / genes / DNA passed from parents (reject chromosomes)
for one mark
1
(ii)
genes / genetic information / chromosomes from two parents
alleles may be different
environmental effect / named may have been mutation
any two for 1 mark each
2
[8]
M51.
(a)
(cell) wall
(cell) membrane
cytoplasm
vacuole
for 1 mark each
4
(b)
(i)
A
(ii)
B
for 1 mark each
2
Page 110
(c)
diffusion
(reject osmosis)
for 1 mark
1
[7]
M52.
(a)
woman XX
man XY
for 1 mark each
2
(b)
50% / 1 in 2 / evens / 0.5 / 50:50
for 1 mark
mark scheme for genetic diagram
gametes all correct
genotypes of offspring all correct in relation to gametes
for 1 mark each
1
mark scheme for written explanation
half sperm have X chromosome, half have Y
and
all eggs have X chromosome
50% / 1 in 2 / evens / 0.5 chance of egg being fertilised
by X or Y sperm
for 1 mark each
2
[5]
Page 111
M53.
(a)
(i)
carbon dioxide / CO2
(ii)
oxygen / O2 / O
for 1 mark each
(reject CO)
(reject water vapour)
2
(b)
(provides) energy
for 1 mark
1
[3]
M54.
(a)
(i)
sexual / sex
(ii)
egg / gamete / sex cell / ovum
for 1 mark each
(reject ovule)
2
(b)
(i)
meiosis / reduction
(ii)
mitosis / somatic
for 1 mark each
2
(c)
twice as many (reject answers based on 23 / 46 chromosomes)
for one mark
1
(d)
(i)
information / genes / DNA passed from parents
(chromosomes neutral)
for one mark
1
(ii)
genes / genetic information / chromosomes from two parents
alleles may be different
environmental effect / named may have been mutation
any two for 1 mark each
Page 112
2
[8]
M55.
pancreas produces lipase
which breaks down / digests fats into fatty acids and glycerol
liver produces bile / hydrogen carbonate
which neutralises acids / makes alkaline
provides optimum / best / most effective pH for lipase / enzyme action
bile emulsifies fats / description
increasing the surface area for lipase / enzyme to act on
any five for 1 mark each
(digestion is in stomach / liver / pancreas – penalise only
once)
[5]
M56.
(a)
(i)
carbon dioxide / CO2
(ii)
oxygen / O2 / O
for 1 mark each
(reject CO)
(water vapour neutral)
2
(b)
(provides) energy
for one mark
1
(c)
starch insoluble therefore water not taken in by osmosis
or
sugar is soluble / has small molecules may diffuse out therefore lost
(ignore ref. to cells bursting)
or
Page 113
starch has large molecules
cannot diffuse therefore retained
for 1 mark each
3
[6]
M57.
parental genotypes both correct – both Bb
gamete genotypes all correct B and b
B and b
genotype of bb offspring correctly related to gametes
bb offspring identified as small bolls
for 1 mark each
[4]
M58.
(i)
DNA
(accept RNA)
for one mark
1
(ii)
DNA carries coded information
which controls the order of amino acids
in proteins
for 1 mark each
3
[4]
Page 114