Genetic Concepts · CSEC Biology

52 past-paper questions on Genetic Concepts, part of Continuity and Variation, from every CSEC Biology paper on Quelpr.

1. 1(b)(i)2 marks· Biology Q1 1(b)(i)How do the red blood cells of Katz differ from normal red blood cells?
2. 1(c)3 marks· Biology Q1 1(c)Deduce the genotypes of the parent plants. Explain your answer with the aid of a genetic diagram.
3. 2(b)(i)a)3 marks· Biology Q2 2(b)(i)a)State what is meant by EACH of the following terms: Allele
4. 2(b)(i)b)3 marks· Biology Q2 2(b)(i)b)State what is meant by EACH of the following terms: Genotype
5. 2(b)(i)c)3 marks· Biology Q2 2(b)(i)c)State what is meant by EACH of the following terms: Phenotype
6. 2(b)(ii)6 marks· Biology Q2 2(b)(ii)Using a genetic diagram, explain how two non-albino parents could produce an albino offspring.
7. 2(b)(iii)1 mark· Biology Q2 2(b)(iii)Suggest the genotypes of parents who will never have albino children.
8. 2(c)(ii)2 marks· Biology Q2 2(c)(ii)Suggest TWO characteristics that a farmer may want to keep in his crop of tomato plants.
9. 3(a)3 marks· Biology Q3 3(a)Complete Table 2 to show how sex is inherited in humans.
10. 3(a)(i)3 marks· Biology Q3 3(a)(i)Complete the chart in Figure 3, using letters and words as appropriate, to show the inheritance of flower colour when two pure-breeding varieties of Impatiens are crossed. The heterozygous phenotype is pink.
11. 3(a)(ii)2 marks· Biology Q3 3(a)(ii)If F₁ Impatiens plants were crossed, what would be the phenotypic ratio for flower colour in the offspring?
12. 3(b)(i)2 marks· Biology Q3 3(b)(i)The alleles of the ABO blood group in humans show co-dominance. How does this co-dominance differ from incomplete dominance shown in the inheritance of flower colour in Impatiens illustrated in Figure 3?
13. 3(b)(ii)1 mark· Biology Q3 3(b)(ii)If the Impatiens flowers in Figure 3 showed co-dominance, what would be the phenotype of the F₁ generation?
14. 3(b)(iii)4 marks· Biology Q3 3(b)(iii)In the space provided below, show, by using a genetic diagram, how a child may inherit blood type O from parents who belong to blood groups A and B respectively.
15. 3(c)(i)3 marks· Biology Q3 3(c)(i)Complete the following genetics diagram to illustrate this information. Parents' phenotypes: Male x Female Parents' genotypes: x XHXh Gametes: x (XH)(Xh) Fertilization cross: Gametes XH Xh
16. 3(c)(ii)1 mark· Biology Q3 3(c)(ii)State the probability of the couple having a haemophiliac child.
17. 3(c)(iii)3 marks· Biology Q3 3(c)(iii)What is the likely sex of the haemophiliac child? Give ONE reason to support your answer.
18. 3(d)6 marks· Biology Q3 3(d)A colour-blind woman mates with a man who has normal colour vision. Determine the probability of this couple having a colour-blind daughter by completing the genetic diagram below.
19. 3(d)3 marks· Biology Q3 3(d)A horticulturalist has a crop of plants that produces both red and white flowers. However, more red flowers are produced than white. A red-flowered plant is crossed with a white-flowered plant and the offspring produced…
20. 3(d)(i)4 marks· Biology Q3 3(d)(i)Complete the genetic diagram below to show how this is possible.
21. 3(d)(ii)1 mark· Biology Q3 3(d)(ii)What is the genotype of the child with blood group O?
22. 4(a)(i)6 marks· Biology Q4 4(a)(i)Distinguish between the following pairs of terms: Allele and gene
23. 4(a)(ii)6 marks· Biology Q4 4(a)(ii)Distinguish between the following pairs of terms: Phenotype and genotype
24. 4(a)(iii)6 marks· Biology Q4 4(a)(iii)Distinguish between the following pairs of terms: Dominant and recessive
25. 4(b)6 marks· Biology Q4 4(b)A certain form of colour-blindness is inherited as a recessive allele carried on the X chromosome. It is thus said to be 'X-linked' or 'sex-linked'. A woman with normal colour vision, whose father is colour-blind, mates…
26. 4(b)5 marks· Biology Q4 4(b)Black fur colour is controlled by a dominant allele, B, and brown fur colour by its recessive allele, b. This characteristic is NOT sex-linked. Give the genotypes of the parents and offspring of a cross between a black…
27. 4(c)4 marks· Biology Q4 4(c)Haemophilia is caused by an X-linked recessive gene. Two parents with the normal phenotype have a haemophiliac child. Use a genetic diagram to show how this is possible. (Xᴺ = normal; Xʰ = gene for haemophilia)
28. 5(a)4 marks· Biology Q5 5(a)Define the terms 'genotype', 'phenotype', 'recessive' and 'dominant'.
29. 5(a)(i)3 marks· Biology Q5 5(a)(i)Parents (P₁) represent pure-breeding dogs for coat colour. In the space provided below, use appropriate symbols to represent the coat colour for both parents and the F₁ generation.
30. 5(a)(i)3 marks· Biology Q5 5(a)(i)Using the chart in Figure 6 above, state the genotypes of family members, 1, 2 and 6.
31. 5(a)(i)2 marks· Biology Q5 5(a)(i)What does the term 'homozygous' mean?
32. 5(a)(ii)5 marks· Biology Q5 5(a)(ii)Complete the genetic diagram below to show what happened the first time the two varieties were crossed, if small flowers are dominant to large flowers.
33. 5(a)(ii)4 marks· Biology Q5 5(a)(ii)Using appropriate stripes, complete the diagrams of the F₂ generation in Figure 6, to show the coat colours of the offspring when the F₁ generation interbreed.
34. 5(b)3 marks· Biology Q5 5(b)Account for the fact that in the ABO system, although there are FOUR different blood groups in existence, only THREE alleles determine these blood groups.
35. 5(b)(i)2 marks· Biology Q5 5(b)(i)Describe TWO symptoms of sickle-cell anaemia.
36. 5(b)(i)2 marks· Biology Q5 5(b)(i)Explain the meaning of the term 'phenotype'.
37. 5(b)(ii)5 marks· Biology Q5 5(b)(ii)Using appropriate symbols, draw a genetics diagram to show the genotypes of the parents and the expected phenotypes of the offspring.
38. 5(b)(ii)5 marks· Biology Q5 5(b)(ii)Fazul and Shanna both carry the sickle-cell trait. What is the chance that a child born to them would suffer from sickle-cell anaemia? Explain your answer with the aid of a genetic diagram. Use the following symbols: A…
39. 5(b)(ii)2 marks· Biology Q5 5(b)(ii)How is the phenotype of an organism determined?
40. 5(b)(ii)a)1 mark· Biology Q5 5(b)(ii)a)How is the oxygen-carrying capacity of the blood reduced by sickle-cell anaemia?
41. 6(a)4 marks· Biology Q6 6(a)Differentiate between an 'allele' and a 'gene'.
42. 6(b)(i)2 marks· Biology Q6 6(b)(i)State what is meant by EACH of the following terms: Homozygous, Heterozygous.
43. 6(b)(i)8 marks· Biology Q6 6(b)(i)Using P as the symbol, state the possible genotypes of the purple flowers.
44. 6(b)(ii)8 marks· Biology Q6 6(b)(ii)A plant breeder obtained flowers that were purple in successive crops of the same plant species. However, in one crop he obtained a few white flowers. Using a genetic diagram, illustrate how he got white flowers in a…
45. 6(b)(ii)6 marks· Biology Q6 6(b)(ii)With the aid of a genetic diagram, show how a man and a woman who do NOT have sickle-cell anaemia can have a child who has the disease.
46. 6(c)9 marks· Biology Q6 6(c)Both parents of a haemophiliac child have the normal blood clotting trait. Use a genetic diagram to explain how this child could inherit the trait for haemophilia.
47. 6(c)(i)6 marks· Biology Q6 6(c)(i)Using the symbols A to represent a normal allele and a to represent the albino allele, draw a genetic diagram to illustrate how two heterozygous parents could produce an albino child.
48. 6(c)(ii)1 mark· Biology Q6 6(c)(ii)Identify the genotype of the albino child.
49. 6(c)(iii)1 mark· Biology Q6 6(c)(iii)State the probability of the albino child being produced.
50. 2(c)(i)1 mark· CSEC Biology · January 2021 · Paper 2State if there is any difference between the function of plant chromosomes and the function of animal chromosomes.
51. 2(c)(ii)1 mark· CSEC Biology · January 2021 · Paper 2State ONE reason for your answer in (c)(i).
52. 5(c)5 marks· CSEC Biology · May/June 2021 · Paper 2With the aid of a genetic diagram, explain how an individual may have a blood type that is different from either parent.