Chromosomes and genes — Paper 2 · IGCSE Sciences - Co-ordinated (Double) 0654

9 What is meant by the term homozygous? A alleles that determine the appearance of an organism B an allele that is effective only when there is no dominant allele present C an individual with two alleles of the same gene that are identical D an individual with two different alleles of the same gene

1 marks

Answer: C

This question in 0654/21 May/June 2017

12 A scientist took a single living cheek cell from each of 30 different people. 15 of these people were male and 15 were female. He stained each cell so that the sex chromosomes could be observed. How many X chromosomes would the scientist observe? A 15 B 30 C 45 D 60

1 marks

Answer: C

This question in 0654/21 May/June 2017

12 A scientist took a single living cheek cell from each of 30 different people. 15 of these people were male and 15 were female. He stained each cell so that the sex chromosomes could be observed. How many X chromosomes would the scientist observe? A 15 B 30 C 45 D 60

1 marks

Answer: C

This question in 0654/22 May/June 2017

12 A scientist took a single living cheek cell from each of 30 different people. 15 of these people were male and 15 were female. He stained each cell so that the sex chromosomes could be observed. How many X chromosomes would the scientist observe? A 15 B 30 C 45 D 60

1 marks

Answer: C

This question in 0654/23 May/June 2017

4 Which statements about X chromosomes in humans are correct? present in present in body cells in body cells of carry genes males females A v v v B v x v Cc J x x D x v x

1 marks

Answer: A

This question in 0654/21 Oct/Nov 2017

4 Which statements about X chromosomes in humans are correct? present in present in body cells in body cells of carry genes males females A v v v B v x v Cc J x x D x v x

1 marks

Answer: A

This question in 0654/22 Oct/Nov 2017

4 Which statements about X chromosomes in humans are correct? present in present in body cells in body cells of carry genes males females A v v v B v x v Cc J x x D x v x

1 marks

Answer: A

This question in 0654/23 Oct/Nov 2017

11 What contains only the information to produce a specific protein? A chromosome B cytoplasm C gene D nucleus

1 marks

Answer: C

This question in 0654/21 Oct/Nov 2018

11 Which sex chromosomes need to be present in a sperm cell to produce a male zygote? A X only B Y only C XX D XY

1 marks

Answer: B

This question in 0654/22 May/June 2019

11 Chimpanzee gametes contain one more chromosome than human gametes. What is the chromosome number in a chimpanzee diploid cell? A 23 B 24 C 46 D 48

1 marks

Answer: D

This question in 0654/21 May/June 2020

11 The diagram shows eggs and sperm containing sex chromosomes. 1 2 3 4 egg X X X X Y Y 5 6 7 8 sperm X Y X X X Y Which row gives the correct combination of sex chromosomes for a male and female offspring? male female offspring offspring A 1 and 8 3 and 7 B 2 and 6 2 and 5 C 3 and 8 1 and 7 D 4 and 6 2 and 5

1 marks

Answer: B

This question in 0654/21 May/June 2023

11 Which row about the nucleus of human cells is correct? description number of example of nucleus chromosomes of cell A diploid 23 gamete B diploid 46 body C haploid 23 body D haploid 46 gamete

1 marks

Answer: B

This question in 0654/22 May/June 2024

11 Which row shows the sex chromosomes in humans? female male A XX XY B XY XX C YY XX D XX YY

1 marks

Answer: A

This question in 0654/23 May/June 2024

11 Some information about a donkey and a horse is shown. ● The sperm from a donkey is able to fertilise the egg from a horse. ● The nucleus of a body cell from a horse has 64 chromosomes. ● The nucleus of a sperm cell from a donkey has 31 chromosomes. ● The offspring from a cross between a donkey and a horse is called a mule. How many chromosomes are in the nucleus of a body cell from a mule? A 31 B 63 C 64 D 95

1 marks

Answer: B

This question in 0654/22 May/June 2025

12 Chimpanzee gametes contain one more chromosome than human gametes. What is the chromosome number in a chimpanzee diploid cell? A 23 B 24 C 46 D 48

1 marks

Answer: D

This question in 0654/21 Oct/Nov 2025

12 Which combination of chromosomes produces a male in humans? A XO B XY C YY D XX

1 marks

Answer: B

This question in 0654/22 Oct/Nov 2025

9 Sheep have 54 chromosomes in their body cells. Which row is correct for a female sheep? number of chromosomes egg cells in egg cells A 27 haploid B 54 haploid C 27 diploid D 54 diploid

1 marks

Answer: A

This question in 0654/23 Oct/Nov 2025