Complete Figure 7 to show the chromosome content of the cells that would result from a normal meiotic division of the diploid parent cell shown in Figure 6.

If two diploid (2n) gametes fuse at fertilisation, it can result in the growth of a tetraploid plant which has 4 copies of each chromosome. Red clover is a plant grown to produce cattle feed. Tetraploid red clover plants produce a higher yield than diploid red clover plants. Whether a red clover plant produces 2n gametes is genetically controlled.

Scientists investigated the possibility of breeding red clover plants that only produced 2n gametes.

• In breeding cycle 0, they grew red clover plants and identified plants that produced 2n gametes. • In breeding cycle 1, they used the plants producing 2n gametes to produce offspring. • In breeding cycles 2 and 3, they identified plants producing 2n gametes and used these to produce offspring.

Their results are shown in Table 3.

The scientists used the following null hypothesis.

'The proportion of plants that produce 2n gametes will not change from one breeding cycle to the next.'

Complete Table 3 to show the expected number of plants that did not produce 2n gametes and the expected number of plants that did produce 2n gametes after 1 cycle. Give each answer to the nearest whole number.

The scientists calculated a chi-squared value of 50 for their results after cycle 1. The critical value at P = 0.05 is 3.84

What can you conclude from this result?

Use your knowledge of directional selection to explain the results shown in Table 3.