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

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.

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.

This question uses a figure or table from the paper — you'll see it when you practise.