OCR GCSE
Additional Science
Homework B3a Foundation
Molecules of life
1
Draw a line to join each part of a cell with its job.
Part of cell
Cell membrane
Job
is the place where chemical
reactions take place
Cytoplasm
controls the cell
Nucleus
controls which substances
pass into and out of the cell
2
Use the following words to complete the sentences below:
chromosomes; proteins; genes; DNA; code; enzymes; divide; nucleus; microscope;
helix
‘Almost all cells in the human body contain DNA. If you look at a cell through a
powerful _______________, you can see thread-like structures called
_______________ in the _______________ of the cell. They show up most clearly
when the cell is about to _______________. If you take each chromosome and
‘unravel’ it, you will find it is made up of a long strand of _______________, which
contains instructions in the form of a chemical _______________. Two strands are
wound around one another in the form of a double _______________. Four chemical
bases, represented by the letters A, G, C and T, make up the code. In groups of three,
these bases determine the order in which amino acids are joined together to form the
many tens of thousands of _______________ your body needs to develop and work
properly. Sections of DNA that instruct the cells to make proteins and so control all life
processes, through _______________, are called _______________.’
3
Name two chemical reactions that enzymes catalyse in living cells:
(a) _______________ (b) _______________
4
Enzymes are ‘fussy’. Give two conditions that must be optimum (just right) if enzymes
are to work efficiently.
(a) _______________ (b) _______________
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OCR GCSE
Additional Science
Homework B3a Higher
Molecules of life
1
Use the following words to complete the sentences below:
chromosomes; proteins; genes; DNA; code; enzymes; divide; nucleus; microscope; G;
three; helix
‘Almost all cells in the human body contain DNA. If you look at a cell through a
powerful _______________, you can see thread-like structures called
_______________ in the _______________ of the cell. They show up most clearly
when the cell is about to _______________. If you take each chromosome and
‘unravel’ it, you will find it is made up of a long strand of _______________, which
contains instructions in the form of a chemical _______________. Two strands are
wound around one another in the form of a double _______________. Four chemical
bases, represented by the letters A, _______________, C and T, make up the code. In
groups of _______________, these bases determine the order in which amino acids are
joined together to form the many tens of thousands of _______________ your body
needs to develop and work properly. Sections of DNA that instruct the cells to make
proteins and so control all life processes, through _______________, are called
_______________.’
2
When DNA replicates, the double helix ‘unzips’ to form two single strands. How are
the new double strands formed?
___________________________________________________________________________
3
Look at the diagram below, showing the double strand of DNA. Using the same
symbols as in the diagram, add the missing bases.
G C
C G
T A
G C
A
T
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OCR GCSE
Additional Science
Homework B3b Foundation
Diffusion
1
Complete the following sentence: ‘Diffusion is the movement of a substance from a
_____________________________________________________________________
2
Name two substances that diffuse from the mother’s blood to the foetal blood across the
placenta.
(a) __________________ (b) ___________________
3
Name two substances that diffuse out of leaves through the stomata.
(a) __________________ (b) ___________________
4
The diagram shows an air sac (alveolus) of the lung and its blood supply.
moist lining
air sac
(alveolus)
carbon
dioxide
oxygen
capillary
red blood cells
The arrows show the direction of diffusion of oxygen and carbon dioxide during
gaseous exchange.
(a) How many layers of cells does oxygen diffuse through before it reaches a red blood
cell? __________________
(b) Describe two other features of the lungs that enable oxygen to be efficiently
absorbed into the blood.
__________________ and __________________
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Additional
OCR GCSE
Additional Science
Homework B3b Higher
Diffusion
1
The diagram shows an air sac (alveolus) of the lung and its blood supply.
moist lining
air sac
(alveolus)
carbon
dioxide
oxygen
capillary
red blood cells
2
The arrows show the direction of diffusion of oxygen and carbon dioxide during
gaseous exchange.
(a) How many layers of cells does oxygen diffuse through before it reaches a red blood
cell? __________________
(b) Describe two other features of the lungs that enable oxygen to be efficiently
absorbed into the blood.
__________________ and __________________
3
Look at the diagram of a villus in the small intestine. Like the alveolus, it has a good
blood supply to make absorption efficient.
food
blood
villus
in the small intestine
Write down two more features that make absorption efficient in these places.
____________________________________
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OCR GCSE
Additional Science
Homework B3c Foundation
Keep it moving
1
Look at the diagram of the heart. Label A–H
A ……………………….
………………………. F
………………………. G
B ……………………….
C ……………………….
D ……………………….
E ……………………….
………………………. H
2
Why is the left ventricle wall thicker than the right ventricle wall?
_________________________________________________________
3
Explain why the heart contains valves.
_________________________________________________________
4
Blood contains red blood cells.
(a) What is the job of a red blood cell?
_________________________________________________________
(b) The structure of a red blood cell is different to the structure of a white blood cell.
Write down one way the structure of a red blood cell is different.
_________________________________________________________
(c) Which part of the blood carries dissolved food?
____________________
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OCR GCSE
Additional Science
Homework B3c Higher
Keep it moving
1
Look at the diagrams of the blood vessels.
Cross section of blood vessels (not to scale)
blood vessel X
blood vessel Y
blood vessel Z
muscle tissue
(a) Some blood vessels carry high-pressure blood away from the heart. Name this type
of blood vessel.
_____________________
(b) Which diagram shows this type of blood vessel? Choose X, Y or Z.
(c) Explain why you chose this diagram.
___________________________________________________________________
(d) Blood vessel Y has special features to make the blood flow in only one direction.
(i) What are these features?
_____________________
(ii) How do these features work?
_______________________________________________________________
(e) Some blood vessels allow materials to move in and out of the blood.
(i) Write down the name of the blood vessels that exchange materials with the
tissues.
_____________________
(ii) This type of blood vessel has special features to allow the exchange of
materials. Explain how these special features allow the exchange of materials.
_______________________________________________________________
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OCR GCSE
Additional Science
Homework B3d Foundation
Divide and rule
1
The diagram shows the nucleus of an animal cell at the start of meiosis (reduction
division).
(a) Name an organ where meiosis takes place. ______________________
(b) Name the structures shown inside the nucleus. ___________________
(c) Complete the diagram below to show a nucleus produced after meiosis.
(d) What is the name of this type of cell? ______________________
(e) If it joins with another, similar cell what will be formed? __________
(f) What is this joining process called? ______________________
2
The diagram below shows a sperm cell highly magnified.
acrosome
nucleus (head)
mitochondria
tail
(a) How is the acrosome important to the job of the sperm?
___________________________________________________________
(b) Why are there such a large number of mitochondria in such a small cell?
___________________________________________________________
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OCR GCSE
Additional Science
Homework B3d Higher
Divide and rule
1
The diagram below shows a sperm cell highly magnified.
acrosome
nucleus (head)
mitochondria
tail
(a) How is the acrosome important to the job of the sperm?
__________________________________________________________________
(b) Why are there such a large number of mitochondria in such a small cell?
__________________________________________________________________
2
The diagram shows different stages of mitosis in a cell.
(a) Complete the diagram. Draw in the missing parts on stage C.
(b) Look at stage E. Both the cells in stage E have the same features as the parent cell
in stage A. Explain why.
__________________________________________________________________
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OCR GCSE
Additional Science
Homework B3e Foundation
Growing up
1
The diagram shows an animal cell. Add labels to the diagram from the list:
cell membrane
2
cell wall
vacuole
cytoplasm
List three things that a plant cell has that are not found in an animal cell.
__________
3
nucleus
__________
__________
Arrange the following phases of human growth in the correct order:
adolescence
old age
maturity
infancy
childhood
1 __________ 2 __________ 3 __________ 4 __________ 5 __________
4
Look at the diagram showing the relative proportions of people at different ages.
Years of age
1
3
6
10
19
At each age, calculate the size of the head as a percentage of the overall body length. Write
your answers on the diagram, below the feet of each person.
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OCR GCSE
Additional Science
Homework B3e Higher
Growing up
1
Arrange the following phases of human growth in the correct order:
adolescence
old age
maturity
infancy
childhood
1____________ 2____________ 3____________ 4____________ 5____________
2
Look at the diagram showing the relative proportions of people at different ages.
Years of age
1
3
6
10
19
At each age, calculate the size of the head as a percentage of the overall body length.
Write your answers on the diagram, below the feet of each person.
3
List three ways in which plant growth differs from animal growth.
(a) _________________________________________________________________
_________________________________________________________________
(b) _________________________________________________________________
_________________________________________________________________
(c) _________________________________________________________________
_________________________________________________________________
4
(a) What are stem cells? ________________________________________________
(b) Why are scientists carrying out stem cell research? ________________________
_________________________________________________________________
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OCR GCSE
Additional Science
Homework B3f Foundation
Controlling plant growth
1
Match, with a linking line, the hormone effect with its possible use in agriculture.
Hormone effect
A
B
Makes plants grow so
Possible use
1
Makes stored
fast that they become
cereals and potatoes
distorted and die
keep longer
Makes seeds and
2
Makes dwarf plants
3
Weedkiller
4
Rooting cuttings
buds inactive
C
Causes roots to
develop on stems
D
Stops the section of
stem between leaves
from getting long
2
The diagram shows three sets of young plants grown under different conditions
1
light
2
light from all directions
3
no light
dark
box
(a) Name the type of growth response shown by the stems in 1. ____________________
(b) State the advantage of this type of response to the plant.
_____________________________________________________________________
(c) Give two differences in appearance between plants 2 and 3.
_____________________________________________________________________
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OCR GCSE
Additional Science
Homework B3f Higher
Controlling plant growth
1
The diagram shows three sets of young plants grown under different conditions.
1
2
light from all directions
light
3
no light
dark
box
(a) Name the type of growth response shown by the stems in 1.
_____________________________________________________________________________
(b) State the advantage of this type of response to the plant.
_____________________________________________________________________________
(c) Give two differences in appearance between plants 2 and 3.
Plants in 2
Plants in 3
(d) From the observations, form a conclusion concerning the effect of light on the rate
of stem growth.
_________________________________________________________________________
2
A new hormone-based weedkiller was tested before being sold to farmers for use on grazing
land. An area of grassland was marked out into five test areas. Different strengths of the
weedkiller were sprayed onto the five test areas. The results of the test are shown.
Strength of weedkiller (%)
0
1
2
4
8
Amount of grass damaged (%)
0
0
2
7
21
Amount of weeds killed (%)
0
12
77
89
98
(a) What is the purpose of spraying with 0% weedkiller? ______________________________
(b) What strength will the manufacturer recommend? _________________________________
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OCR GCSE
Additional Science
Homework B3g Foundation
New genes for old
1
(a) What is a mutation? _______________________
(b) Suggest two causes of mutations.
____________________________________________
____________________________________________
(c) Sometimes an organism shows a new characteristic as a result of a mutation that it
then passes on to its offspring. In which type of cell must this mutation have
occurred?
____________________________________________
2
(a) Describe two important differences between cows.
____________________________________________
____________________________________________
(b) One important difference is milk yield. In a herd of cows, some will produce more
milk than others. If the farmer wanted to improve the milk yield of his herd, which
cows and bulls would he breed together?
________________________________________
(c) One cow is healthy, eats the same amount of food as the other cows but has a poor
milk yield. Suggest why.
________________________________________
(d) Farmers often choose animals to mate together to improve yield. Crop plants can
also be mated together to produce improved crops. Underline the name which best
describes this method of producing farm animals and crops:
adaptation cloning genetic engineering intensive farming selective breeding
3
Give three examples of genetic engineering.
_________________________________________
_________________________________________
_________________________________________
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OCR GCSE
Additional Science
Homework B3g Higher
New genes for old
1
(a) Describe two important differences between cows.
________________________________________
________________________________________
(b) One important difference is milk yield. In a herd of cows, some will produce more
milk than others. If the farmer wanted to improve the milk yield of his herd, which
cows and bulls would he breed together?
_______________________________________
(c) One cow is healthy, eats the same amount of food as the other cows but has a poor
milk yield. Suggest why.
_______________________________________
(d) Farmers often choose animals to mate together to improve yield. Crop plants can
also be mated together to produce improved crops. Underline the name which best
describes this method of producing farm animals and crops:
adaptation cloning genetic engineering intensive farming selective breeding
2
Give three examples of genetic engineering.
______________________________________________
______________________________________________
______________________________________________
3
Artificial selection can result in problems of inbreeding and reduction in the gene pool.
What is wrong with that? Explain as clearly as you can.
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
4
List the four principles of genetic engineering.
_____________________________________
_____________________________________
_____________________________________
_____________________________________
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OCR GCSE
Additional Science
Homework B3h Foundation
More of the same
1
Look at the picture of the spider plant.
Spider plants can reproduce using asexual reproduction. Describe how they do this.
Draw on the diagram to help you explain.
______________________________________________________________________
______________________________________________________________________
_____________________________________________________________________
2
Many types of plants can be grown by taking cuttings.
(a) Why do cuttings from a particular plant all produce the same colour of flower as
the parent plant?
___________________________________________________________________
(b) Why do cuttings from a particular plant all produce the same colour as each other?
___________________________________________________________________
3
What are the advantages of producing plants by tissue culture techniques?
______________________________________________________________________
______________________________________________________________________
4
Scientists have discovered that they can produce animals with identical genes by
cloning. One way to do this is to remove the nucleus of an unfertilised egg cell and
replace it with a nucleus from a body cell. The egg cell, with its new nucleus, can then
grow into a new individual. Give the main difference in the amount of genetic material
between the nucleus that has been removed and the one that has replaced it.
______________________________________________________________________
______________________________________________________________________
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OCR GCSE
Additional Science
Homework B3h Higher
More of the same
1
What are the advantages of producing plants by tissue culture techniques?
______________________________________________________________________
______________________________________________________________________
2
Scientists have discovered that they can produce animals with identical genes by
cloning. One way to do this is to remove the nucleus of an unfertilised egg cell and
replace it with a nucleus from a body cell. The egg cell, with its new nucleus, can then
grow into a new individual.
(a) Give the main difference in the amount of genetic material between the nucleus
that has been removed and the one that has replaced it.
___________________________________________________________________
___________________________________________________________________
(b) More recent experiments have been carried out by removing the nucleus from an
egg cell of a rabbit. A liver cell from another rabbit was used to provide a nucleus
that was then placed into the egg. This is shown below.
nucleus
transferred
liver cell
from rabbit B
egg cell from
rabbit A
nucleus removed
egg replaced in
womb of rabbit A
baby rabbit
Which rabbit, A or B, will the baby rabbit look like? _______________
Why? _____________________________________________________________
___________________________________________________________________
___________________________________________________________________
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OCR GCSE
Additional Science
Homework Mark Scheme
B3a & B3b Foundation & Higher
B3a Molecules of life
B3b Diffusion
Foundation
Foundation
1
Cell membrane: controls which
1
High to low concentration
[2]
substances pass into and out of the cell
2
(a) oxygen/sugar
[1]
(b) amino acids/minerals
[1]
3
carbon dioxide/oxygen/water
[2]
4
(a) 2
[1]
Nucleus: controls the cell
Cytoplasm: is the place where chemical
reactions take place
2
[2]
Microscope; chromosomes; nucleus;
(b) Moist lining/large surface area/well
divide; DNA; code; helix; proteins;
3
4
vascularised
enzymes; genes
[5]
(a) respiration
[1]
Higher
(b) photosynthesis/protein synthesis
[1]
1
(a) temperature
(b) pH
[1]
[1]
1
(a) 2
[1]
(b) Moist lining/large surface area/well
2
Higher
[2]
vascularised
[2]
Large surface area/thin wall
[2]
Microscope; chromosomes; nucleus;
divide; DNA; code; helix; G; three;
proteins; enzymes; genes
[6]
2
Complementary base pairing
[1]
3
T, A (in that order from top down)
[2]
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OCR GCSE
Additional Science
Homework Mark Scheme
B3c & B3d Foundation & Higher
B3c Keep it moving
B3d Divide and rule
Foundation
Foundation
1
A – Aorta
(a) ovaries/testes
[1]
B – Pulmonary vein
(b) chromosomes
[1]
C – Left atrium
(c) two chromosomes (one long, one
1
D – Bicuspid/mitral valve
short)
E – Left ventricle
(d) sex cell/gamete
[1]
F – Pulmonary artery
(e) zygote
[1]
(f) fertilisation
[1]
G – Vena cava
H – Right ventricle
[8]
2
Pump blood around body – more work
[1]
3
Prevent blood backflow (going the
4
[1]
2
(a) To get through the egg membrane at
fertilisation
[1]
(b) Because it needs lots of energy to
wrong way)
[1]
(a) Carry oxygen
[1]
(b) No nucleus or full of haemoglobin
[1]
(c) Plasma
[1]
swim
[1]
Higher
1
(a) To get through the egg membrane at
fertilisation
Higher
1
[1]
(b) Because it needs lots of energy to
(a) artery
[1]
(b) X
[1]
(c) thick wall
[1]
(d) (i) valves
[1]
2
[1]
(a) Show four chromosomes going to
each pole of the cell
[2]
(b) Because mitosis produces an exact
copy
(ii) When blood goes wrong way,
fill with blood and close vein
swim
[1]
[1]
(e) (i) capillaries
[1]
(ii) thin walls
[1]
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OCR GCSE
Additional Science
B3e Growing up
B3f Controlling plant
growth
Foundation
1
2
3
Homework Mark Scheme
B3e & B3f Foundation & Higher
Top to bottom:
Foundation
nucleus
[1]
cell membrane
[1]
cytoplasm
[1]
cell wall
[1]
vacuole
[1]
chloroplasts
[1]
1
A3; B1; C4; D2
[3]
2
(a) Positive phototropic response
[2]
(b) Shoots grow towards the light for
photosynthesis
(c) 2 – short and compact; 3 – long and
etiolated
Higher
1
3 adolescence
(a) Positive phototropic response
[2]
(b) Shoots grow towards light for
4 maturity
photosynthesis
5 old age [2. 1 mark for one incorrect position]
31%; 25%; 21%; 18%; 15%
[1]
(c) 2 – short and compact; 3 – long and
[5]
etiolated
Higher
1
[2]
1 infancy
2 childhood
4
[1]
[2]
(d) Less light, more stem growth in
1 infancy
length
2 childhood
2
3 adolescence
[1]
(a) Control
[1]
(b) 2–4%
[2]
4 maturity
5 old age [2, 1 mark for one incorrect position]
2
31%; 25%; 21%; 18%; 15%
[5]
3
cell enlargement
[1]
cell division mainly restricted to tips
[1]
plant cells retain ability to differentiate
[1]
(a) undifferentiated cells
[1]
4
(b) to replace differentiated cells,
e.g. nerves
[1]
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OCR GCSE
Additional Science
Homework Mark Scheme
B3g & B3h Foundation & Higher
B3g New genes for old
B3h More of the same
Foundation
Foundation
1
(a) Change in a gene
[1]
(b) Radiation and chemicals
[2]
(c) Gamete/sex cell
[1]
(a) Milk/beef/hide/health, etc.
[2]
1
plant. Small, genetically identical plant
2
2
Drawing of a runner coming from parent
on end.
[2]
(a) Genetically identical
[1]
(b) Genetically identical
[1]
(b) Cows with good milk yield and
3
bulls with family history of good
milk yield
3
exactly desirable characteristics
[2]
(c) Genetically different
[1]
(d) Selective breeding
[1]
Produce large number of plants with
4
[1]
Nucleus removed – haploid; replacement
nucleus – diploid (twice the genetic
information)
[2]
Any three of insulin production/GM
Higher
crops/strawberries that have better
keeping characteristics, etc.
[3]
1
Produce large number of plants with
exactly the same desirable characteristics
Higher
1
2
(a) Milk/beef/hide/health, etc.
[2]
(b) Cows with good milk yield and
milk yield
2
(a) Nucleus removed – haploid;
replacement nucleus – diploid
(twice the genetic information)
bulls with family history of good
[1]
[2]
(b) It will look like rabbit B, because
[2]
(c) Genetically different
[1]
(d) Selective breeding
[1]
the nucleus came from B’s liver cell
[2]
Any three of insulin production/GM
crops/strawberries that have better
keeping characteristics, etc.
3
Less variation/recessive characteristics
show
4
[3]
[2]
Selection of characteristics; isolation of
genes; insertion; replication
[4]
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OCR GCSE
Additional Science
Self-assessment quiz
B3a Foundation and Higher
Molecules of life
1
Complete the crossword below to reveal the word in the shaded column
[F]
1
2
3
4
5
6
7
2
1
Cell organelles that provide energy for life processes
2
The name given to DNA copying itself
3
Protein production
4
The spiral arrangement of a DNA molecule
5
A biological catalyst
6
The control centre of a cell
7
Thread-like structures found in nuclei
True or false? Put T or F in the boxes.
[F]
Enzymes are proteins
Proteins are made of chains of sugars
The DNA molecule is arranged as a triple helix
DNA copies itself before cells divide
3
How many DNA bases are needed to code for one amino acid? _______________
4
(a) Where in the body are some amino acids changed into others? _______________
(b) What is this process called? _______________
5
[H]
Arrange the following according to size by numbering them 1–5, with 1 for the smallest
and 5 for the largest: chromosomes ___; genes ___; DNA ___; nucleus ___; cell ___.
6
[H]
[F]
Complete the following sentence: ‘Enzymes are biological _______________. They are
made out of _______________. They have a special, or _______________, pH and
_______________ at which they work best. Enzymes catalyse the chemical reactions
7
occurring in _______________.’
[F]
Describe the two phases of DNA replication. _________________________________
[H]
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OCR GCSE
Additional Science
Self-assessment quiz
B3b Foundation and Higher
Diffusion
1
Complete the crossword below to find the word in the shaded column
[F]
1
2
3
4
5
6
7
2
1
Large _______________ area increases diffusion rates
2
These are thin with a large surface area to allow gaseous exchange to occur
3
Finger-like projection that increases the surface area of the small intestine
4
Substances diffuse from a high to low _______________
5
_______________ diffuses out of the leaf after it has been made by photosynthesis
6
Oxygen diffuses across the ____________ from mother’s blood to the foetus’ blood
7
Substances diffuse across _________ membranes easily
True or false? Put T or F in the boxes.
[F]
Waste substances diffuse from the foetal blood to the mother’s blood across the
placenta
Oxygen diffuses into plant leaves during the daytime
Substances diffuse into and out of a cell through the cell membrane
Carbon dioxide diffuses from the alveoli into the bloodstream
3
Complete the sentence: ‘Diffusion is a result of the _______________ movement of
individual _______________ from a region of _______________ to low
_______________’.
4
[H]
State two ways in which leaves are adapted to increase the rate of diffusion of oxygen
and carbon dioxide. (a) _______________ (b) _______________
5
How do transmitter substances cross synapses to carry signals from one neurone to the
next? _______________________
6
[H]
[H]
State three ways in which the small intestine is adapted to speed the absorption of food:
(a) _______________ (b) _______________ (c) _______________
[H]
22 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz
B3c Foundation and Higher
Keep it moving
1 Draw lines linking components (parts) of the blood with their function (job).
2
Parts of blood
Job
Red blood cell
clots the blood
Plasma
carries dissolved substances
Platelets
defends the body against disease
White blood cells
carries oxygen around the body
[F]
True or false? Put T or F in the boxes.
[F]
Hormones are carried by red blood cells
The right atrium pumps blood to the lungs
The left ventricle has the thickest wall of all the heart chambers
Red blood cells do not have a nucleus
3
Give three differences between arteries and veins.
Arteries
4
[F]
Veins
Arrange the following parts of the circulatory system into the correct sequence, starting
with the blood entering the heart from the body. (Number them 1, 2, 3, … 10):
lungs __; body __; left ventricle __; pulmonary artery __; aorta __; right atrium __; left
atrium __; vena cava __; right ventricle __; pulmonary vein __
5
[F]
Why do capillaries have thin walls? __________________________________________
______________________________________________________________.
6
(a) Complete the following equation:
Oxygen + haemoglobin
__________________
(b) Where in the body does this reaction occur? _____________
7
[H]
Why does the heart have semilunar, bicuspid and tricuspid valves?
___________________________________
8
[H]
[F]
Name the fatty substance that forms plaques in blood vessels and can block arteries.
[H]
________________
23 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz
B3d Foundation and Higher
Divide and rule
1
Complete the crossword below to find the word in the shaded column.
[F]
1
2
3
4
5
6
7
2
1
Sex cell
2
Male sex cell
3
Growth division
4
Formed when two sex cells join together
5
This is how the sperm reaches the egg
6
The ‘normal’ number of chromosomes
7
The sperm uses this special adaptation to get into the egg
True or false? Put T or F in the boxes.
[F]
Sperm have a diploid number of chromosomes
New cells for growth are produced by mitosis
Meiosis halves the normal number of chromosomes
Gametes are produced by meiosis
3
Complete the following sentence: ‘Sperm cells and ____ cells are both sex cells, or
__________. They are produced by ________. They have the ________ number of
chromosomes. When sex cells join together at ______________ they produce a _______.
4
This will have the ________ number of chromosomes.
[F]
Give three advantages of an organism being multicellular:
[F]
______________________________________
______________________________________
______________________________________
5
In which type of cell division are chromosomes copied exactly to produce genetically
identical cells? ________
[H]
24 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz
B3e Foundation and Higher
Growing up
1
Complete the crossword below to find the word in the shaded column.
[F]
1
2
3
4
5
6
7
2
1
A phase of human growth, sometimes called adolescence
2
The first phase of human growth
3
The parts of plant shoot or root where cell division normally takes place
4
Most of the cell’s activity takes place here.
5
Only plant cells have a large one full of cell sap.
6
What stem cells do when they become specialised
7
Type of cell that can develop into different cells, tissues and organs
True or false? Put T or F in the boxes.
[F]
Both plant and animal cells have nuclei
Plant cells do not have cell walls
Adolescence is the first phase of human growth
3
Plants can grow continuously
List the main phases of human growth:
(a) ______ (b) ________ (c) __________________ (d) ________________ (e) ________
4
[F]
List the three parts of cells plants and animals have in common.
(a) ________ (b) ______________ (c) __________
[F]
5
What are undifferentiated cells called? __________
[F]
6
Give one difference between plant and animal growth. ______________________
7
_____________________________________________________
[H]
What is ‘cell differentiation’? ________________
[F]
25 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: answers
B3f Foundation and Higher
Controlling plant growth
1
Complete the crossword below to find the word in the shaded column.
[F]
1
2
3
4
5
6
7
2
1
Growth response to light
2
A non-active phase of development
3
Producing flowers
4
A directional response to a stimulus
5
Growth response to gravity
6
Plant hormone
7
Using plant hormones to remove unwanted plants
True or false? Put T or F in the boxes.
[F]
Shoots are negatively phototropic
Plant hormones can be used to control fruit ripening
Auxin affects cell elongation
Roots grow upwards in response to gravity
3
Underline the one of these plant processes that is not controlled by plant hormones:
growth of shoots and roots; _______________; flowering; ripening of fruits
4
[F]
Give two commercial uses of plant hormones:
_____________________________________________________
[F]
5
What is a phototropic response? ___________________________
[F]
6
i
Are plant roots positively or negatively geotropic? __________________
ii
What does this mean? _______________________
[F]
Where is auxin made in a plant? __________________
[H]
7
26 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz
B3g Foundation and Higher
New genes for old
1
Complete the crossword below to identify the word in the shaded column
[F]
1
2
3
4
5
6
7
2
1
Codes for one particular protein
2
The amount produced
3
Hormone produced for diabetics by genetic modification of bacteria
4
One cause of mutations
5
A change in the DNA base sequence
6
Sexual reproduction between organisms
7
A type of breeding that involves choosing suitable offspring
True or false? Put T or F in the boxes.
[F]
Mutations can occur spontaneously
Mutations are a change in the DNA base sequence
All mutations are harmful
Selective breeding can improve agricultural yields
3
Give two examples of causes of mutations. ________ and ________
4
Describe the three phases of selective breeding. _________________________,
[F]
_________________________ and _________________________
[F]
5
Give one example of genetic engineering. ___________________________________
[F]
6
Describe the four principles (phases) of genetic engineering.
________________________
________________________
________________________
________________________
[H]
27 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz
B3h Foundation and Higher
More of the same
1
Identify the correct order of the outline cloning technique used in cow embryo
transplants by numbering them 1–5.
embryos split, forming clones __
selected cows artificially inseminated __
sperm collected from selected bulls __
embryo clones implanted into surrogate cows __
2
embryos collected __
[F]
True or false? Put T or F in the boxes.
[F]
Identical twins are naturally occurring clones
Spider plants do not reproduce asexually
Organs suitable for transplants could be produced by cloning
Dolly was the first animal cloned from an adult
3
Give one advantage and one disadvantage to the commercial use of cloned plants:
Advantage
4
Disadvantage
Complete the following sentence: ‘Cloning is a type of ___________ reproduction.
It produces __________ identical copies.’
5
[F]
Why is cloning plants easier than cloning animals?
__________________________________________________
6
[F]
[H]
Identify the correct order of the cloning technique used to produce Dolly the sheep
by numbering each step 1–4.
cell implanted into another sheep __
egg cell nucleus replaced with the nucleus from an udder cell __
cell grows into the clone of the sheep from which the udder cell came __
nucleus removed from an egg cell __
[H]
28 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: answers
B3a Foundation and Higher
Molecules of life
1
Complete the crossword below to reveal the word in the shaded column
1
5
7
2
m
i
t
c
h
o
n
d
r
i
e
o
p
2
r
l
i
c
a
t
i
o
e
s
i
s
3
4
s
y
n
t
h
h
e
l
i
x
e
n
z
y
m
e
6
n
u
c
l
e
u
s
r
o
m
o
s
o
m
e
c
h
[F]
a
n
s
1
Cell organelles that provide energy for life processes
2
The name given to DNA copying itself
3
Protein production
4
The spiral arrangement of a DNA molecule
5
A biological catalyst
6
The control centre of a cell
7
Thread-like structures found in nuclei
True or false? Put T or F in the boxes.
[F]
Enzymes are proteins
T
Proteins are made of chains of sugars
F
The DNA molecule is arranged as a triple helix
F
DNA copies itself before cells divide
T
3
How many DNA bases are needed to code for one amino acid? 3
4
(a) Where in the body are some amino acids changed into others? Liver
(b) What is this process called? Transamination
5
[H]
Arrange the following according to size by numbering them 1–5, with 1 for the smallest
and 5 for the largest: chromosomes 3; genes 2; DNA 1; nucleus 4; cell 5.
6
[H]
[F]
Complete the sentence: ‘Enzymes are biological catalysts. They are made out of
protein. They have a special, or optimum, pH and temperature at which they work best.
7
Enzymes catalyse the chemical reactions occurring in living cells.’
[F]
Describe the two phases of DNA replication. Helix unzipping and base pairing.
[H]
29 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: answers
B3b Foundation and Higher
Diffusion
1
Complete the crossword below to find the word in the shaded column
1
4
s
c
u
o
7
2
r
f
a
c
e
2
3
l
e
a
v
e
s
v
i
l
l
u
s
c
e
n
t
r
a
t
5
o
x
y
g
e
n
6
p
l
a
c
e
n
t
t
h
i
n
n
i
o
[F]
n
a
1
Large _______________ area increases diffusion rates
2
These are thin with a large surface area to allow gaseous exchange to occur
3
Finger-like projection that increases the surface area of the small intestine
4
Substances diffuse from a high to low _______________
5
_______________ diffuses out of the leaf after it has been made by photosynthesis
6
Oxygen diffuses across the ____________ from mother’s blood to the foetus’ blood
7
Substances diffuse across _________ membranes easily
True or false? Put T or F in the boxes.
Waste substances diffuse from the foetal blood to the mother’s blood across the
[F]
F
placenta
3
Oxygen diffuses into plant leaves during the daytime
F
Substances diffuse into and out of a cell through the cell membrane
T
Carbon dioxide diffuses from the alveoli into the bloodstream
F
Complete the sentence: ‘Diffusion is a result of the random movement of individual
particles from a region of high to low concentration.’
4
State two ways in which leaves are adapted to increase the rate of diffusion of oxygen
and carbon dioxide. i thin. ii large surface area
5
[H]
How do transmitter substances cross synapses to carry signals from one neurone to the
next? by diffusion
6
[H]
[H]
State three ways in which the small intestine is adapted to speed the absorption of food:
(a) large surface area. (b) permeable surface. (c) good blood supply
[H]
30 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: answers
B3c Foundation and Higher
Keep it moving
1 Draw lines linking components (parts) of the blood with their function (job).
2
3
4
Parts of blood
Job
Red blood cell
clots the blood
Plasma
carries dissolved substances
Platelets
defends the body against disease
White blood cells
carries oxygen around the body
[F]
True or false? Put T or F in the boxes.
[F]
Hormones are carried by red blood cells
F
The right atrium pumps blood to the lungs
F
The left ventricle has the thickest wall of all the heart chambers
T
Red blood cells do not have a nucleus
T
Give three differences between arteries and veins.
[F]
Arteries
Veins
Thick wall/high-pressure blood
Thin wall/low-pressure blood
Carrying blood from heart
Carrying blood to heart
Deep seated/no valves
Closer to surface/valves
Arrange the following parts of the circulatory system into the correct sequence, starting
with the blood entering the heart from the body. (Number them 1, 2, 3, … 10):
lungs 5; body 10; left ventricle 8; pulmonary artery 4; aorta 9; right atrium 2; left
atrium 7; vena cava 1; right ventricle 3; pulmonary vein 6
5
Why do capillaries have thin walls? So that there are only short distances for
diffusion to exchange materials between the blood and tissues.
6
oxyhaemoglobin
(b) Where in the body does this reaction occur? in the lungs
[H]
Why does the heart have semilunar, bicuspid and tricuspid valves?
To prevent the backflow of blood
8
[H]
(a) Complete the following equation:
Oxygen + haemoglobin
7
[F]
[F]
Name the fatty substance that forms plaques in blood vessels and can block arteries.
cholesterol
[H]
31 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: answers
B3d Foundation and Higher
Divide and rule
1
Complete the crossword below to find the word in the shaded column.
1
2
4
7
2
3
a
z
c
g
a
m
e
t
s
p
e
r
m
3
m
i
t
o
y
g
o
t
e
5
s
w
i
m
6
d
i
p
l
o
r
o
s
o
m
e
[F]
e
s
i
s
i
d
1
Sex cell
2
Male sex cell
3
Growth division
4
Formed when two sex cells join together
5
This is how the sperm reaches the egg
6
The ‘normal’ number of chromosomes
7
The sperm uses this special adaptation to get into the egg
True or false? Put T or F in the boxes.
[F]
Sperm have a diploid number of chromosomes
F
New cells for growth are produced by mitosis
T
Meiosis halves the normal number of chromosomes
T
Gametes are produced by meiosis
T
Complete the following sentence: ‘Sperm cells and egg cells are both sex cells, or
gametes. They are produced by meiosis. They have the haploid number of
chromosomes. When sex cells join together at fertilisation they produce a zygote. This
4
will have the diploid number of chromosomes.
[F]
Give three advantages of an organism being multicellular:
[F]
Allows the organism to be larger
Allows for cell differentiation
Allows the organism to be more complex
5
In which type of cell division are chromosomes copied exactly to produce genetically
identical cells? mitosis
[H]
32 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: answers
B3e Foundation and Higher
Growing up
1
Complete the crossword below to find the word in the shaded column.
1
4
c
6
2
3
y
d
p
t
i
u
b
e
r
t
y
2
i
n
f
a
3
t
i
p
s
o
p
l
a
s
m
5
v
a
c
u
o
l
e
f
f
e
r
e
n
t
i
7
s
t
e
m
n
c
y
a
t
e
1
A phase of human growth, sometimes called adolescence
2
The first phase of human growth
3
The parts of plant shoot or root where cell division normally takes place
4
Most of the cell’s activity takes place here.
5
Only plant cells have a large one full of cell sap.
6
What stem cells do when they become specialised
7
Type of cell that can develop into different cells, tissues and organs
[F]
True or false? Put T or F in the boxes.
[F]
Both plant and animal cells have nuclei
T
Plant cells do not have cell walls
F
Adolescence is the first phase of human growth
F
Plants can grow continuously
T
List the main phases of human growth:
(a) infancy (b) childhood (c) adolescence (puberty) (d) maturity (adulthood)
(e) old age
4
[F]
List the three parts of cells plants and animals have in common.
(a) nucleus (b) cell membrane (c) cytoplasm
[F]
5
What are undifferentiated cells called? stem cells
[F]
6
Give one difference between plant and animal growth. Plant cell division mainly
7
restricted to tips/plants retain ability to differentiate
[H]
What is ‘cell differentiation’? specialisation
[F]
33 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: answers
B3f Foundation and Higher
Controlling plant growth
1
Complete the crossword below to find the word in the shaded column.
4
7
2
3
w
e
1
p
h
o
t
o
t
r
o
2
d
o
r
m
a
n
c
y
i
n
g
p
i
c
3
f
l
o
w
e
r
t
r
o
p
i
s
m
5
g
e
o
t
r
o
6
a
u
x
i
n
d
k
i
l
l
e
e
p
[F]
i
r
1
Growth response to light
2
A non-active phase of development
3
Producing flowers
4
A directional response to a stimulus
5
Growth response to gravity
6
Plant hormone
7
Using plant hormones to remove unwanted plants
True or false? Put T or F in the boxes.
[F]
Shoots are negatively phototropic
F
Plant hormones can be used to control fruit ripening
T
Auxin affects cell elongation
T
Roots grow upwards in response to gravity
F
Underline the one of these plant processes that is not controlled by plant hormones:
growth of shoots and roots; photosynthesis; flowering; ripening of fruits
4
c
[F]
Give two commercial uses of plant hormones:
rooting powder/fruit ripening; weedkiller/dormancy control
[F]
5
What is a phototropic response? A growth response to/from light
[F]
6
i
Are plant roots positively or negatively geotropic? positively geotropic
ii
What does this mean? growing towards gravity
[F]
Where is auxin made in a plant? in the growing tip
[H]
7
34 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: answers
B3g Foundation and Higher
New genes for old
1
Complete the crossword below to identify the word in the shaded column
3
i
6
2
n
s
1
g
e
n
l
d
e
2
y
i
e
u
l
i
n
4
5
c
h
e
m
i
c
a
l
m
u
t
a
t
i
o
n
v
e
b
r
e
e
d
i
n
g
7
s
e
l
e
c
t
i
[F]
1
Codes for one particular protein
2
The amount produced
3
Hormone produced for diabetics by genetic modification of bacteria
4
One cause of mutations
5
A change in the DNA base sequence
6
Sexual reproduction between organisms
7
A type of breeding that involves choosing suitable offspring
True or false? Put T or F in the boxes.
[F]
Mutations can occur spontaneously
T
Mutations are a change in the DNA base sequence
T
All mutations are harmful
F
Selective breeding can improve agricultural yields
T
3
Give two examples of causes of mutations. radiation and chemicals
4
Describe the three phases of selective breeding. characteristic selection,
[F]
cross breeding and selection of suitable offspring
[F]
5
Give one example of genetic engineering. insulin production/herbicide resistance
[F]
6
Describe the four principles (phases) of genetic engineering:
selection of characteristics
isolation of genes
insertion
replication
[H]
35 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: answers
B3h Foundation and Higher
More of the same
1
Identify the correct order of the outline cloning technique used in cow embryo
transplants by numbering them 1–5.
embryos split, forming clones 4
selected cows artificially inseminated 2
sperm collected from selected bulls 1
embryo clones implanted into surrogate cows 5
2
3
embryos collected 3
[F]
True or false? Put T or F in the boxes.
[F]
Identical twins are naturally occurring clones
T
Spider plants do not reproduce asexually
F
Organs suitable for transplants could be produced by cloning
T
Dolly was the first animal cloned from an adult
F
Give one advantage and one disadvantage to the commercial use of cloned plants:
Advantage
Disadvantage
Sure of characteristics – genetically identical
Lack of genetic variation
Mass produce difficult plants
If one plant gets a disease, all will
[F]
be susceptible to it
4
Complete the following sentence: ‘Cloning is a type of asexual reproduction.
It produces genetically identical copies.’
5
Why is cloning plants easier than cloning animals?
Many plant cells retain the ability to differentiate.
6
[F]
[H]
Identify the correct order of the cloning technique used to produce Dolly the sheep
by numbering each step 1–4.
cell implanted into another sheep 3
egg cell nucleus replaced with the nucleus from an udder cell 2
cell grows into the clone of the sheep from which the udder cell came 4
nucleus removed from an egg cell 1
[H]
36 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Student checklist B3
Living and growing
Tick () column: A when you have covered the
statement in class.
Tick () column B if you need to do more work on it.
Tick () column C when you are confident you can
answer any questions on it.
In your revision for your end-of-block test or final
examinations, concentrate most time on those
statements not ticked.
Statements in bold can only appear on the Higher
tier paper.
I can:
1
A
B
C
Identify parts of the cell and describe their function
State that the coded information is carried in the form of DNA in genes on
chromosomes
State that one gene codes for one protein and that most have their effect by the
production of enzymes
Describe the biological importance of enzymes and their specificity for the
substrate.
Interpret data on DNA fingerprinting
Describe the structure and copying of DNA and its role in protein
synthesis
State that some amino acids can be changed into others and that
proteins have particular sequences of amino acids that determine
their shape and function
Use a microscope
Prepare a temporary slide
2
Describe diffusion and its effect on the movement of molecules into and out of
cells
Describe the movement of substances such as digested food and gases into the
blood stream and across the placenta in terms of diffusion
Describe the movement of gases into and out of leaves and explain their loss of
water in terms of diffusion
Explain the effects of three factors on diffusion rates and relate these
to gaseous exchange and food absorption.
Explain the diffusion of transmitter substances across synapses
Examine slides with a microscope at high power
3
Describe the structure and operation of the heart and how it and the blood
vessels transport substances around the body.
Explain that cholesterol build-up in arteries is linked to diet and can restrict
blood flow
Describe the problems associated with mechanical and biological heart
replacements
Explain the advantage of a double circulatory system
Explain the adaptations of arteries, veins and capillaries to their functions.
37 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Student checklist B3
Describe advantages and disadvantages of pacemakers and valve
replacement over heart transplants
Can perform a simple dissection
4
Explain the advantages of being multicellular
Explain that cells need to be replaced by mitosis, which maintains the diploid
number of chromosomes.
Explain the basic points of meiosis and mitosis
State that sexual reproduction involves haploid gametes combining to form a
diploid zygote
State that gametes are produced by meiosis, which introduces variation.
Explain how sperm and egg structure are adapted to their function
5
Identify and describe the importance of chloroplasts, vacuole and cell wall in a
plant cell.
Describe how to make a stained slide of an onion cell.
Compare animal and plant cells.
Describe the differences between animal and plant growth.
Describe the main phases of human growth, explain and manipulate data on
differential growth rates.
State that undifferentiated (stem) cells can develop into different cells, tissues
and organs.
Discuss issues arising from stem cell research.
6
Discuss issues arising from stem cell research and state the photo and geotropic
responses of shoot and root.
Describe an experiment to demonstrate positive phototropic response in shoots.
State that auxins move in solution and are involved in phototropism and
geotropism and relate the action of plant hormones to their commercial uses.
Interpret data from phototropic experiments and explain how auxin causes
shoot curvature.
7
Explain that mutations are a change in the DNA base sequence, how they are
caused and that, usually harmful, they may be beneficial.
Describe the process of selective breeding and explain how this can contribute
to improved agricultural yields.
Define, with examples, genetic engineering/modification and explain some of
the advantages and risks.
Describe the principles of genetic engineering and discuss the moral and
ethical issues involved
8
Describe cloning technique in cows; recall advantages of cloning and recognise
that there are ethical dilemmas.
Describe asexual reproduction in plants and the advantages and disadvantages
associated with commercial cloning.
Describe the cloning techniques used to produce Dolly the sheep and discuss
the benefits and risks in cloning and the implications and dilemmas
involved.
38 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Student checklist B3
Describe cloning by tissue culture and explain why cloning plants is easier
than cloning animals.
Can carry out aseptic techniques
39 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Student checklist B3
40 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.