Variation — Paper 2 · IGCSE Biology (9-1) 0970

28 Specific grape varieties are maintained using stem cuttings from mature plants that are then planted and cultivated to produce grapes. This is an example of artificial asexual reproduction. What is a disadvantage of using asexual reproduction to produce fruit? A An outbreak of disease will affect the whole crop in the same way. B Genetically identical fruit is produced relatively quickly. C No pollination or pollinators are required. D The characteristics of the grapes will vary between plants.

1 marks

Answer: A

This question in 0970/21 May/June 2018

29 Which two statements are correct for the process of cross-pollination in plants? 1 increases potential for variation in offspring 2 pollen is transferred to a different flower on the same plant 3 reduces potential to respond to environmental change 4 pollen is transferred to a flower on a different plant of the same species A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

1 marks

Answer: B

This question in 0970/21 May/June 2018

33 The diagram shows the bases on part of a chromosome, P, responsible for the production of normal haemoglobin. The same part of another chromosome, Q, is responsible for the production of sickle-cell haemoglobin. G A G G T G C T C C A C chromosome P chromosome Q What has caused the difference between the two chromosomes? A discontinuous variation B gene mutation C phenotypic variation D selective breeding

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2018

40 In 1991 there were only fourteen Daviesia cunderdin plants. What happens to a plant population that becomes very small? A Each plant will produce fewer offspring. B Each plant will produce more offspring. C Variation in the population is increased. D Variation in the population is reduced.

1 marks

Answer: D

This question in 0970/22 Oct/Nov 2018

35 Which statement describes how a species becomes adapted to its environment? A Genetic similarities give rise to different genotypes which may have a reproductive advantage. B Genetic variation gives rise to different phenotypes which may have a reproductive advantage. C Phenotypic similarities give rise to different genotypes which may have a reproductive advantage. D Phenotypic variation gives rise to different phenotypes which may have a reproductive advantage.

1 marks

Answer: B

This question in 0970/21 May/June 2019

32 The diagram shows a genetic cross between a male bird with black feathers and a female bird with white feathers. All of the offspring have blue feathers. parents FBFB × FWFW black white offspring FBFW 100% blue Two of the blue offspring are crossed. Which row shows the correct phenotype percentages for the cross? percentage percentage percentage black blue white A 25 75 0 B 25 50 25 C 50 20 25 D 75 0 25

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2019

33 The graph shows the masses of two different types of tomato. type 1 type 2 number of tomatoes 0 20 40 60 80 100 120 140 160 180 200 220 240 mass / g What can be concluded from the graph? A Genes do not affect the mass of tomatoes. B Type 1 tomatoes show continuous variation. C Type 2 tomatoes are sometimes smaller than type 1 tomatoes. D Type 2 tomatoes show discontinuous variation.

1 marks

Answer: B

This question in 0970/21 May/June 2020

27 Asexual reproduction can be used to produce crops. Why might a disease be likely to spread throughout the whole crop? A crop plants are genetically different B crop plants are genetically identical C many offspring are produced D offspring are produced quickly

1 marks

Answer: B

This question in 0970/22 May/June 2020

33 The graph shows the masses of two different types of tomato. type 1 type 2 number of tomatoes 0 20 40 60 80 100 120 140 160 180 200 220 240 mass / g What can be concluded from the graph? A Genes do not affect the mass of tomatoes. B Type 1 tomatoes show continuous variation. C Type 2 tomatoes are sometimes smaller than type 1 tomatoes. D Type 2 tomatoes show discontinuous variation.

1 marks

Answer: B

This question in 0970/22 May/June 2020

33 What is not affected by the environment? A height B skin colour C blood group D weight

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2020

29 Scientists carried out a survey on the effect of giving up smoking on the risk of developing lung cancer. The results are shown in the graph. continued smoking 15 percentage 10 cumulative risk of developing lung cancer stopped smoking at 60 years of age 5 stopped smoking at 30 years of age never smoked 0 45 55 65 75 age, in years, of people surveyed The scientists made three conclusions: 1 Stopping smoking reduces the risk of developing lung cancer. 2 Age increases the risk of lung cancer for smokers and non-smokers. 3 The earlier people stop smoking, the lower the risk. Which conclusions are correct? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: A

This question in 0970/21 May/June 2021

35 The graph shows the percentage of different blood groups in a human population. 40 30 percentage in 20 the population 10 0 A B AB O blood group Which type of variation is shown by human blood groups? A continuous variation caused by genetic and environmental factors B continuous variation caused by genetic factors only C discontinuous variation caused by genetic and environmental factors D discontinuous variation caused by genetic factors only

1 marks

Answer: D

This question in 0970/21 May/June 2021

29 Commercial plant growers use asexual reproduction to grow coffee plants which produce crops of coffee beans. What is a disadvantage of asexual reproduction? A The coffee beans produced by all of the plants are identical. B Two parent plants are needed. C One parent is needed. D All plants are equally susceptible to the same disease.

1 marks

Answer: D

This question in 0970/22 Oct/Nov 2021

33 Which term is a genetic change? A allele B genotype C mutation D phenotype

1 marks

Answer: C

This question in 0970/21 May/June 2023

33 Which types of variation can be inherited? variation caused by | variation caused by genes the environment A v Jv key B v Xx v/=yes Cc x v X =no D x x

1 marks

Answer: B

This question in 0970/22 May/June 2023

29 What is a disadvantage of sexual reproduction for a population in the wild? A a reduction in genetic diversity B a decreased ability to adapt to changes in the environment C a reduction in reproduction if individuals are isolated D an increased likelihood of a disease affecting all individuals

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2023

30 Pollen grains from a plant were placed onto the stigma of a flower of the same plant. The lengths of the pollen tubes were measured for four hours. (The mean length of the style in this species of plant is 2 mm.) This was repeated using pollen from a different plant. The results are shown. 3500 pollen from a different plant 3000 2500 mean length 2000 of the pollen tubes / μm 1500 1000 500 pollen from the same plant 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 time / hours Which statements are correct? 1 Self-pollination does not lead to fertilisation. 2 The difference in growth of the two types of pollen is an adaptation to increase variation. 3 The pollen tubes from a different plant grew fastest between 2.0 hours and 4.0 hours. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2023

34 What are sources of genetic variation in populations? 1 meiosis 2 random mating 3 random fertilisation A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: A

This question in 0970/22 Oct/Nov 2023

38 Red-green colour blindness is a sex-linked characteristic caused by a recessive allele. Which prediction can be made about the children of a woman who is colour-blind and a man with normal vision? A Boys will be colour-blind, and girls will have a 50% chance of being colour-blind. B Boys will be colour-blind, and girls will have normal vision. C Girls will be colour-blind, and boys will have a 50% chance of being colour-blind. D Girls will be colour-blind, and boys will have normal vision.

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2023

29 Bacteria such as MRSA are resistant to antibiotics. These processes can occur in bacteria. 1 artificial selection 2 genetic variation 3 mutation 4 natural selection Which processes lead to the development of antibiotic resistance? A 1, 2, 3 and 4 B 1, 2 and 3 only C 2, 3 and 4 only D 2 and 4 only

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2024

33 Which statement about gene mutations is correct? A A mutation is a change in the amino acid sequence of DNA. B Mutations are a source of genetic variation. C Mutations are caused by random mating. D Mutations happen during random fertilisation.

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2024

30 A farmer bred together male cattle with white hair and female cattle with red hair. All the offspring produced had roan hair (a mixture of red and white). He then repeatedly bred together two roan cattle, and the offspring were in the ratio of 1 red : 2 roan : 1 white. What explains why the farmer obtained this ratio? A The red phenotype is dominant to the white phenotype. B The roan phenotype is an example of codominance. C The roan phenotype is dominant to the red phenotype and the white phenotype. D The white phenotype is dominant to the red phenotype.

1 marks

Answer: B

This question in 0970/21 May/June 2025

32 What is a way in which new alleles are formed? A artificial selection B mutation C natural selection D sexual reproduction

1 marks

Answer: B

This question in 0970/22 May/June 2025

24 The diagram shows parts of two different plants, 1 and 2, of the same species. The transfer of pollen between the flowers of these two plants is shown by the arrows labelled P and Q. P Q 1 2 Which arrows show cross-pollination, and which transfer of pollen would produce the most variation in the offspring? transfer of pollen that produces the cross-pollination most variation in the offspring A P only P B P only Q C P and Q P D P and Q Q

1 marks

Answer: A

This question in 0970/22 Oct/Nov 2025

32 The photograph shows a speckled chicken. Speckled chickens have white feathers and black feathers. When a chicken with only white feathers and a chicken with only black feathers are crossed, all of the offspring are speckled. What would be the expected phenotypic ratio if a speckled chicken was crossed with a chicken with only white feathers? A all offspring have only white feathers B all offspring are speckled C 1 white feathers only : 1 speckled D 3 white feathers only : 1 speckled

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2025