- Remind pupils of the differences between external and internal fertilisation. Ask them about the numbers of eggs and sperm in each case and to suggest reasons for any differences. Find out what pupils know about human egg cells,
eg where they are produced, how often they are produced, and how a woman might know if she is pregnant or not. Using pupils' suggestions and video or CD-ROM simulation introduce the stages of the monthly cycle.
- Help the pupils to construct a diagram of the days in the cycle, marking when menstruation and ovulation might occur and when the uterus lining is thickening. Discuss with pupils the variation in cycle length and practise calculating when a woman might ovulate and when her period is due. Explain that the menstrual cycle also prepares the uterus for a fertilised egg and identify the time in the cycle when fertilisation is most likely.
- Establish that, on the whole, humans have one offspring at a time and that the human reproductive system is designed to try to make sure that the one offspring survives.
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- describe the changes of the menstrual cycle,
eg egg maturation, ovulation, menstruation
- recognise egg production as a cyclic activity
- make calculations,
eg ovulation date and menstruation date, for a regular cycle
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