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4 marksPatterns of Inheritance

CAPE Biology Unit 1 · 2004 · Paper 2 · Question 3(b)(i)

Cross-breeding the F₁ produced the F₂ pumpkins of which 357 were orange globe, 126 were orange bottle, 119 were green globe and 39 green bottle pumpkins. Table 1 and the Chi squared test may be used to determine the probability that the differences between the observed results and the expected results are due to chance alone.

Complete Table 1 to determine the probability that the differences between the observed and expected results are due to chance.

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Other parts of this question

  1. 3(a)In the space below, using appropriate symbols for these characteristics, set out the genetic cross which produces the F₁ plants.[3 marks]
  2. 3(b)(ii)x² is calculated from the formula Σ (O - E)² / E. Determine the value of x² from the data in Table 1. Use Table 2 to select the critical x² value.[1 mark]
  3. 3(c)(i)State the critical value of x² from Table 2.[1 mark]
  4. 3(c)(ii)Do your results imply a significant or insignificant difference between the observed and expected results?[1 mark]

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