Quelpr
2 marksPatterns of Inheritance

CAPE Biology Unit 1 · May/June 2024 · Paper 2 · Question 2(a)(i)

A test cross in tomato plants involving fruit shape (ox-heart or plum) and fruit size (cherry or beefsteak) with dihybrid genotype OoBb crossed to a pure-bred plant yielding plum, cherry fruit produced 620 offspring with phenotypes: Oxheart, beefsteak (160); Oxheart, cherry (155); Plum, beefsteak (165); Plum, cherry (140).

State the expected offspring phenotype ratio of the test cross.

The mark scheme is shown once you've answered.

Practise this question

Other parts of this question

  1. 2(a)(ii)Complete the shaded boxes in Table 1 to determine the value of chi-squared (χ²), to two decimal places.[4 marks]
  2. 2(a)(iii)Outline a suitable conclusion based on the results obtained in (a)(ii), if the critical chi-squared value for three degrees of freedom at p = 0.05 is 7.82.[2 marks]
  3. 2(b)(i)State TWO features of restriction enzymes.[2 marks]
  4. 2(b)(ii)List THREE advantages associated with the use of genetically modified organisms.[3 marks]
  5. 2(b)(iii)List THREE disadvantages associated with the use of genetically modified organisms.[3 marks]
  6. 2(b)(iv)On the grid provided on page 15, plot the data shown in Table 2 as a line graph and draw a curve of best fit.[5 marks]
  7. 2(c)Explain if EACH of the methods shown in Figure 4 can produce DNA that the bacterium E. coli can use to make amylase on a large scale. Present your response in…[9 marks]

More practice: the rest of this paper · more Patterns of Inheritance questions · all CAPE Biology Unit 1 past papers