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3 marksGenetic Concepts

CSEC Biology · January 2015 · Paper 2 · Question 1(c)

The plant from which the flower shown in Figure 1B comes, exists in two varieties: one produces blue flowers while the other produces white flowers. A cross between two blue-flowered plants produces 100 seeds. Seventy-four of the plants that develop from these 100 seeds have blue flowers while 26 have white flowers.

Deduce the genotypes of the parent plants. Explain your answer with the aid of a genetic diagram.

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Other parts of this question

  1. 1(a)(i)Identify the type of reproduction carried out by EACH of the plant organs shown in Figure 1. A: B:[2 marks]
  2. 1(a)(ii)Outline the sequence of events that would take place from pollination to the formation of the seed/fruit from the organ shown in Figure 1B.[3 marks]
  3. 1(b)Describe TWO differences between the outcomes of cell division by mitosis and cell division by meiosis.[4 marks]
  4. 1(d)(i)Measure the length of the radicle of the seedling on EACH day and record your measurements in Table 1.[1 mark]
  5. 1(d)(ii)Plot the data in Table 1 on the graph paper below. Put days on the horizontal (x) axis.[4 marks]
  6. 1(d)(iii)State TWO factors, other than water, that are required for the germination of the seed shown in Figure 2.[2 marks]
  7. 1(d)(iv)Describe an investigation to test the hypothesis, 'Water is needed for the germination of seeds'.[4 marks]
  8. 1(e)Suggest why the cotyledons (seed leaves) become smaller as the primary leaves increase in size.[2 marks]

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