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2 marksPatterns of Inheritance

CAPE Biology Unit 1 · 2016 · Paper 2 · Question 2(b)(i)

A plant geneticist is studying the inheritance of bitter taste (Su) and explosive rind (e) in watermelon. Explosive rind is recessive, and non-bitter is homozygous recessive (su). A test cross was performed between a bitter, non-explosive plant and a plant homozygous recessive for both traits to determine if the genes assort independently. Table 1 shows the offspring phenotypes and numbers.

Determine the genotype of EACH phenotypic category in Table 1, using the symbols given. Write your answers in Table 1.

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Other parts of this question

  1. 2(a)(i)Using a simplified diagram of a small section of ribonucleic acid (RNA), describe the structure of RNA. Note: Details of the chemical composition of components…[5 marks]
  2. 2(a)(ii)Comment on the role of m-RNA in eukaryotes.[2 marks]
  3. 2(b)(ii)Suggest a null hypothesis for the test cross in (b).[2 marks]
  4. 2(b)(iii)Complete Table 2 by writing the missing values in the relevant spaces.[2 marks]
  5. 2(b)(iv)Using the table of probabilities provided below, and with reference to the calculated Chi-square value from Table 2, evaluate the validity of the hypothesis.[2 marks]

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