AQA GCSE Biology (8461), Higher tier · Inheritance, variation and evolution › Variation and evolution
Practise Cloning. 11 exam-style questions plus unlimited generated ones on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
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In adult cell cloning, what is used to stimulate the egg cell to divide to form an embryo?
An electric shock
Explain why the nucleus was removed from the egg cell of sheep B.
So that the embryo only contains the genetic information from sheep A
In adult cell cloning, from which type of cell is the nucleus removed?
An (unfertilised) egg cell
The steps in adult cell cloning are given below, but they are in the wrong order. A The nucleus is removed from an unfertilised egg cell. B An electric shock stimulates the egg cell to divide and form an embryo. C A nucleus from a body (skin) cell of the animal to be cloned is inserted into the egg cell. D The embryo is inserted into the uterus of an adult female (a surrogate mother). Write the letters in the correct order.
A, C, B, D
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy4 marks
Plants and animals can be cloned in several ways.
(a) Which cloning method involves splitting apart the cells of a developing animal embryo before they become specialised? Tick (✓) one box.[1]
Adult cell cloning
Cuttings
Embryo transplants
Tissue culture
(b) Which method is an older, simple way that gardeners use to produce many identical new plants from a parent plant? Tick (✓) one box.[1]
Adult cell cloning
Cuttings
Embryo transplants
Selective breeding
(c) Tissue culture uses small groups of cells from part of a plant to grow identical new plants. Give one reason why tissue culture is important.[1]
(d) In adult cell cloning, what is used to stimulate the egg cell to divide to form an embryo?[1]
Show the answer and mark scheme
(a)Answer: Embryo transplants
(b)Answer: Cuttings
(c)Answer: Preserving rare plant species / producing large numbers of identical plants commercially in nurseries
preserving rare plant species / producing many identical plants for nurseries (commercially)
(d)Answer: An electric shock
an electric shock
Question 2Medium6 marks
Scientists used adult cell cloning to produce a lamb. • The nucleus was removed from an unfertilised egg cell taken from sheep B. • The nucleus from a skin cell of sheep A was inserted into this egg cell. • The embryo that developed was placed in the uterus of sheep C.
(a) Describe what was done to make the egg cell develop into an embryo after the nucleus from sheep A was inserted.[2]
(b) Which sheep is the lamb genetically identical to? Explain your answer.[2]
(c) Explain why the nucleus was removed from the egg cell of sheep B.[1]
(d) Give one possible benefit of adult cell cloning in agriculture.[1]
Show the answer and mark scheme
(a)Answer: An electric shock stimulated the egg cell to divide (by mitosis) to form an embryo, a ball of cells
an electric shock (was given)
to stimulate the egg cell to divide / to form an embryo (a ball of cells)
(b)Answer: Sheep A, because the nucleus containing the genetic information came from sheep A
sheep A
the nucleus / genetic information / DNA came from sheep A
(c)Answer: So that the embryo only contains the genetic information from sheep A
so the embryo contains only the genetic information of sheep A / so there are not too many chromosomes
(d)Answer: Many copies of an animal with a desirable characteristic, e.g. high milk yield, can be produced
produce many animals with a desirable characteristic (e.g. high milk yield) / copy the best animals
Question 3Hard7 marks
A farmer owns a cow that produces a very high yield of milk. The farmer wants more cows with this characteristic. Two possible methods are embryo transplants and adult cell cloning.
(a) In embryo transplants, the cells of the embryo are split apart before they become specialised. Explain why the cells must be split apart at this stage.[1]
(b) Compare embryo transplants and adult cell cloning as ways of producing more cows with a very high milk yield.[6]
Show the answer and mark scheme
(a)Answer: Unspecialised cells can still develop into any type of cell, so each one can grow into a complete animal
unspecialised cells can develop into any type of cell / each cell can develop into a whole animal
(b)Answer: Level 3 answers describe both methods and compare the genetic outcome, reliability and drawbacks, reaching a justified conclusion
embryo transplants: the high-yield cow is fertilised (e.g. artificial insemination with bull sperm)
the embryo is removed and split apart before the cells become specialised; each part is transplanted into a host mother
the calves are identical to each other but not to the high-yield cow, because half their genes come from the bull, so they may not have a high yield
adult cell cloning: the nucleus from a body cell of the high-yield cow is inserted into an egg cell whose nucleus has been removed
an electric shock makes the egg divide; the embryo is inserted into the uterus of a host cow
the calf is genetically identical to the high-yield cow, so it has the same alleles for high milk yield
adult cell cloning has a low success rate and is expensive; clones may have health problems
both methods reduce genetic variation, so the herd could be wiped out by one disease
milk yield is also affected by the environment (e.g. diet), so clones may not produce the same yield
a justified conclusion, e.g. adult cell cloning is the only method that copies this particular cow
Marked with levels of response: the full level descriptors are in the app.