Quelpr
1 markPatterns of Inheritance

CAPE Biology Unit 1 · 2011 · Paper 2 · Question 2(b)(i)

In pea plants, tall (T) plants are dominant over short (t) plants, and round seeds (R) are dominant over wrinkled seeds (r). A cross between two heterozygous tall, round-seeded plants produced the following progeny: Tall plants with round seeds (98), Tall plants with wrinkled seeds (46), Short plants with round seeds (44), Short plants with wrinkled seeds (14).

Based on the type of cross, deduce the expected ratio of the phenotypes.

The mark scheme is shown once you've answered.

Practise this question

Other parts of this question

  1. 2(a)(i)State the term which describes the interaction of these two genes.[1 mark]
  2. 2(a)(ii)Define the terms 'allele' and 'dominant'.[2 marks]
  3. 2(a)(iii)In the space provided, draw a genetic diagram to explain the cross.[5 marks]
  4. 2(b)(ii)formulate a possible null hypothesis for the Chi-square test.[1 mark]
  5. 2(b)(iii)State the formula for, and determine the number of degrees of freedom in the Chi-square test performed in (b)(ii), briefly explaining any terms used.[2 marks]
  6. 2(b)(iv)Use the calculated value of χ² (10.81) and the probabilities provided in Table 2 to find the probability of the results of the cross departing significantly by…[1 mark]
  7. 2(b)(v)What conclusion may be drawn from the probability found in (b)(iv)?[2 marks]

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