Reproduction

30 During the division of a nucleus by meiosis, changes can happen that produce a gamete with an abnormal number of genes or an abnormal number of chromosomes. Which change can result in a child having Down’s syndrome? A a gamete with one extra chromosome B a gamete with one less gene C a gamete with one less chromosome D a gamete with one extra gene

5090/21/O/N/25 © UCLES 2025 1 Fig. 1.1 shows the female human reproductive system as viewed from the front. B A D C E Fig. 1.1 (a) Identify the letter on Fig. 1.1 that has been used to label the area where each of the following happens: where sperm is deposited ...................................... where oestrogen is produced ...................................... where implantation occurs. ...................................... [3] (b) Some women can have blockages in the tubes labelled B. Explain why this would prevent them becoming pregnant. ................................................

Describe the conditions required for seeds to germinate.

Fig. 1.1 shows that the seed changes between day 1 and day 4. Describe these changes and explain how they happen.

Name the part of the seed that X has developed from.

The seed is germinating in darkness. Explain what causes X and Y to grow in opposite directions.