Scientists have discovered how to produce genetically modified (GM) hens’ eggs.

1
Some proteins produced in GM eggs can be used as drugs to treat humans.

The diagram shows how this is done.

(a) Which type of reproduction is involved when the cockerel mates with the hen?

Tick ( ) one box.

Asexual

Cloning

Sexual

(1)

Page 1 of 23
(b) From which part of a human are the genes cut?

Tick ( ) one box.

Chromosome

Embryo

Glands

(1)

(c) Read the information about genetically modified animals.

• GM animals might escape and breed with wild animals.

• Genetic modification can produce fast-growing animals for food.

• Genetic modification can be used to clone animals in danger of extinction.

• Using GM animals can reduce the number of animals used in medical research.

• Animals have the right to be free from genetic modification.

Use only this information to answer these questions.

(i) Give two reasons why many people are in favour of genetically modified animals.

1.

2.
(2)

(ii) Give two reasons why many people are against genetically modified animals.

1.

2.
(2)
(Total 6 marks)

Page 2 of 23
 The family tree shows the inheritance of a disorder caused by a dominant allele.
2
Fiona and Eric have two children George and Harriet.

(a) The son, George, has the disorder.

The daughter, Harriet, does not have the disorder.

(i) Use the key to draw the symbol for Harriet next to her name on the family tree.
(2)

(ii) The symbol D represents the dominant allele for the disorder.
The symbol d represents the recessive allele.

Fiona has the pair of alleles dd.

Write the correct pairs of alleles in the boxes.

Harriet has the pair of alleles

A person with the disorder could have

the pair of alleles or the pair of alleles

(3)

Page 3 of 23
 (b) Before Harriet was born, a doctor suggested that Fiona should have the embryo
‘screened’.

(i) Give one reason why the doctor suggested screening.

Tick ( ) one box.

To check for the D allele

To check the sex of the embryo

To cure the disorder

(1)

(ii) Why do some people believe that embryos should not be screened?

(1)
(Total 7 marks)

(a) Human body cells contain 46 chromosomes.

3

(i) How many chromosomes are there in a human sperm cell?

(1)

(ii) Name the part of the sperm cell that contains the chromosomes.

(1)

(b) Draw a ring around the correct answer to complete each sentence.

X and X.

(i) In human females, the sex chromosomes are X and Y.

Y and Y.

(1)

Page 4 of 23
 X and X.

(ii) In human males, the sex chromosomes are X and Y.

Y and Y.

(1)

(c) A man might release 300 million sperm cells at a time.

How many of these sperm cells would contain an X chromosome?

(1)
(Total 5 marks)

Humans reproduce sexually.

4
Draw a ring around the correct answer to complete each sentence.

chromosomes

(a) (i) At fertilisation genes join together.

sex cells

(1)

chromosomes.

(ii) At fertilisation a single cell forms, which has new pairs of nuclei.

sex cells.

(1)

(b) Cystic fibrosis can be inherited by children whose parents do not have it.

two

(i) A person who has cystic fibrosis has three copies of the

four

cystic fibrosis allele.

(1)

Page 5 of 23
 large.

(ii) The cystic fibrosis allele is recessive.

strong.

(1)

(c) The diagram shows a human body cell.

Choose the correct answer from the box to complete each sentence.

cell membrane cell wall cytoplasm nucleus

(i) The part of the cell labelled B is the

(1)

(ii) The part of the cell labelled C is the

(1)

(d) Which part of the cell, A, B, C or D:

(i) contains the allele for cystic fibrosis

(1)

(ii) is affected by cystic fibrosis?

(1)
(Total 8 marks)

Page 6 of 23
 The diagram shows a strawberry plant.
5
The parent plant grows side shoots.

New plants grow on the side shoots.

© D.G. Mackean

The new plants will all have the same inherited characteristics as the original parent plant.

Complete the sentences to explain why.

Use words from the box.

asexual differentiation embryos fertilisation

gametes genes mitosis sexual

(a) The new plant is produced by reproduction.

(1)

(b) In this type of reproduction, body cells divide by

(1)

(c) The new plant has the same as the parent plant.
(1)
(Total 3 marks)

Page 7 of 23
 Soay sheep live wild on an island off the north coast of Scotland. No people live on the island.
6

By Owen Jones = Jonesor [CC-BY-SA-2.5], via Wikimedia Commons

Over the last 25 years, the average height and mass of the wild Soay sheep have decreased.

The scientists think that climate change might have affected the size of the sheep.

(a) More Soay sheep are now able to survive winter than 25 years ago.

What change in the climate may have helped more Soay sheep to survive winters?

(1)

(b) Complete the sentences.

(i) Soay sheep show variation in size because of differences in their

(1)

(ii) The change in the size of the Soay sheep over 25 years can be explained by
Darwin’s

theory of
(1)
(Total 3 marks)

Page 8 of 23
 Maize plants reproduce sexually to form maize cobs.
7 Each maize cob has many seeds.

The colour of the seeds is controlled by a gene.

The gene has two alleles, purple and yellow.

The diagram shows the cobs produced by breeding maize plants.

(a) Use words from the box to complete the sentences.

dominant environmental recessive

(i) The first generation plants show that the purple allele is

(1)

(ii) The second generation plants show that the yellow allele is

(1)

Page 9 of 23
(b) The allele for purple can be represented by the letter A.
The allele for yellow can be represented by the letter a.

(i) What alleles does a yellow seed have?

Draw a ring around one answer.

AA Aa aa

(1)

(ii) What alleles does a purple seed from a first generation plant have?

Draw a ring around one answer.

AA Aa aa

(1)

(c) The drawing shows a cob from one of the second generation plants.

Page 10 of 23
 A student counted 334 purple seeds and 110 yellow seeds on this maize cob.
What is the approximate ratio of purple seeds to yellow seeds on the cob?

Tick ( ) one box.

3 purple : 1 yellow

1 purple : 3 yellow

1 purple : 1 yellow

(1)
(Total 5 marks)

The diagram shows a time line for the evolution of humans.

8

The letters P, Q, R and S show human ancestors.

The letter T shows modern humans.

(a) (i) How many millions of years ago did humans first use fire?

millions of years ago

(1)

Page 11 of 23
 (ii) Which human ancestor, P, Q, R or S, was the first ancestor to use tools?

(1)

(iii) For how many millions of years did human ancestor R live on Earth?

(1)

(b) How do we know that human ancestors P, Q, R and S lived on Earth?

(1)

(c) Which scientist suggested that humans have evolved from ape-like ancestors?

Draw a ring around one answer.

Darwin Mendel Semmelweiss

(1)
(Total 5 marks)

Page 12 of 23
 The diagram shows the family tree of a pair of pigs, A and B.
9 Pigs A and B have four offspring, C, D, E and F.

Some of the pigs have a genetic disorder.

(a) Which pig, A, B, C, D, E or F, is:

(i) a male pig with the genetic disorder

(1)

(ii) a female pig without the genetic disorder?

(1)

(b) Draw a ring around the correct answer to complete the sentences.

Pig C has the genetic disorder.

pig A.

(i) Pig C inherited the genetic disorder from pig B.

pig E.

(1)

Page 13 of 23
 an embryo.

(ii) The gene for the genetic disorder was passed on in an enzyme.

a gamete.

(1)

(c) Pig F is a male.

Complete the diagram to show how the sex of pig F depends on the inheritance of the sex
chromosomes X and Y.

The sex chromosomes of pig B and the egg cells have been completed for you.

(3)
(Total 7 marks)

Page 14 of 23
 When scientists look at dividing cells under a microscope, they can see strands that contain a
10 chemical called DNA.

A photograph of these strands can be cut up and re-arranged.

The diagram shows an arrangement of the strands from a human cell.

(a) What name is given to the strands containing DNA shown in the diagram?

Draw a ring around one answer.

alleles chromosomes genes

(1)

(b) Look carefully at the diagram.

(i) The cell was taken from a man and not from a woman.

How can you tell?

(1)

Page 15 of 23
 (ii) What evidence is there that the strands are from a body cell, and not from a gamete?

Tick ( ) one box.

The strands are arranged in order of size.

The strands are in pairs.

Gametes are made in the testes and ovaries.

(1)

(iii) When a human cell is not dividing the strands containing DNA are not clearly visible.

Draw a ring around the correct answer to complete the sentence.

cell membrane.

In a human cell, the DNA is normally found in the cytoplasm.

nucleus.

(1)
(Total 4 marks)

Cystic fibrosis is an inherited disorder.

11
Mr and Mrs Brown do not have cystic fibrosis but they have a child with cystic fibrosis.

(a) Draw a ring around the correct answer to complete each sentence.

carrier allele.

(i) The allele for cystic fibrosis is a dominant allele.

recessive allele.

(1)

carriers.

(ii) Mr and Mrs Brown are both immune.

infected.

(1)

Page 16 of 23
(b) The diagram shows how the allele for cystic fibrosis can be inherited by Mr and Mrs
Brown’s children.

(i) Give the number of one person in the diagram who has

cystic fibrosis.

(1)

(ii) The chance that Mr and Mrs Brown's next child will have cystic fibrosis is

(1)

(c) A genetic counsellor describes to Mr and Mrs Brown one way of screening embryos for
cystic fibrosis.

• Some eggs are collected from Mrs Brown.

• The eggs are then fertilised in a dish.

• Several embryos may start to develop.

Page 17 of 23
The photograph shows how doctors take one cell from each embryo when it is only 3 days
old.

©Pascal Goetgheluck/Science Photo Library

• The DNA in the cell from each embryo is tested for cystic fibrosis.

• Doctors select one embryo that is unaffected and place it in Mrs Brown’s uterus.

• The embryo then develops into a baby.

Use the information to suggest one advantage and one disadvantage of screening
embryos in this way.

Advantage

Disadvantage

(2)
(Total 6 marks)

Page 18 of 23
Mark schemes
(a) sexual
1 1

(b) chromosome
1

(c) (i) any two from:

ignore answers that do not relate to list

• genetic-engineering can produce fast-growing food animals

• genetic engineering can be used to clone animals in danger of

extinction

• using GM animals can reduce the number of animals used in medical

research
2

(ii) GM animals might escape and breed with wild animals

ignore answers that do not relate to list
1

animals have the right to be free from genetic modification

1
[6]

(a) (i) circle

2
mark independently
1

unshaded
could be in body of script
1

(ii) (Harriet) dd
in first box
1

DD
if another letter is chosen it must be used throughout and upper or
lower case must be clear
1

Dd
1

(b) (i) to check for the D allele.

1

Page 19 of 23
 (ii) any one from:

• may harm / kill foetus / embryo / baby / mother

allow could affect the baby

• immoral / unethical / religion

ignore playing God
ignore references to unnatural
ignore wrong unqualified
ignore expense / prejudice unqualified
ignore lack of permission
ignore results are unreliable
1
[7]

(a) (i) 23
3 1

(ii) nucleus / ‘the head’

allow phonetic spelling
1

(b) (i) X and X

1

(ii) X and Y
1

(c) 150 million / 150,000,000 / half (of them) / 50% / 1 in 2

1
[5]

(a) (i) sex cells

4 1

(ii) chromosomes
1

(b) (i) two

1

(ii) recessive
1

(c) (i) cell membrane

allow membrane
1

(ii) cytoplasm
1

(d) (i) A
1

Page 20 of 23
 (ii) B
1
[8]

(a) asexual
5 1

(b) mitosis
1

(c) genes
1
[3]

(a) warmer / dryer

6
allow greenhouse effect / global warming
ignore wind
1

(b) (i) genes / alleles / chromosomes / DNA / genetic material / genetics

allow inheritance
allow nutrition / food / metabolism / growth rate
ignore environment
1

(ii) natural selection / evolution

allow survival of the fittest
1
[3]

(a) (i) dominant

7
allow clear indication
1

(ii) recessive
allow clear indication
1

(b) (i) aa
extra ring drawn cancels the mark
1

(ii) Aa
extra ring drawn cancels the mark
1

(c) 3 purple : 1 yellow

extra box ticked cancels the mark
1
[5]

(a) (i) 3
8 1

Page 21 of 23
 (ii) Q
1

(iii) 1
1

(b) from fossils / bones

allow artefacts / named artefacts / drawings / evidence of fires
1

(c) Darwin
1
[5]

(a) (i) any one from:

9
• A

• C
1

(ii) any one from:

• B

• D
1

(b) (i) pig A

1

(ii) a gamete
1

(c) XY or YX
1

XY
1

XY or YX
in this order only
1
[7]

(a) chromosomes
10 1

(b) (i) has XY / Y

allow female would be XX / has no Y
1

(ii) The strands are in pairs

1

Page 22 of 23
 (iii) nucleus
1
[4]

(a) (i) recessive allele

11 1

(ii) carriers
1

(b) (i) 6
allow nn
1

(ii) 1 in 4 / 0.25 / / 25 % / 1:3

do not accept ‘3:1’ / 1:4 / 1 in 3 / 25
1

(c) advantage:

detect CF qualified – eg at early stage / before becoming pregnant or (only) healthy

children produced
allow ‘after only 3 days’
allow reduces health care costs
1

disadvantage:

some embryos are destroyed / may damage embryo

allow increased risk of miscarriage
ignore not natural
ignore cost
1
[6]

Page 23 of 23