| Date | November 2009 | Marks available | 3 | Reference code | 09N.2.SL.TZ0.4 |
| Level | Standard level | Paper | Paper 2 | Time zone | TZ0 |
| Command term | Explain | Question number | 4 | Adapted from | N/A |
Question
The diagram below shows the female reproductive system.
Label the diagram above with the letter U to show the uterus.
Outline the role of luteinizing hormone (LH) after ovulation.
Explain how sexual reproduction can lead to variation in a species.
Markscheme
letter U marked/labelled on uterus
Accept in lumen or on wall.
formation of the corpus luteum
allows characteristics from both parents to appear in offspring;
crossing over (during prophase 1) changes chromosome composition;
produces gametes which are all different;
random chance of which sperm fertilizes ovum;
greater variation (resulting from sexual reproduction) favours survival of species through natural selection;
Accept independent assortment during meiosis from AHL.
Examiners report
Almost all candidates could identify the uterus.
An extremely difficult question for most candidates as evidenced by many blank answer spaces. The role of LH after ovulation was just not known. The corpus luteum was rarely mentioned.
A common knowledge among candidates was their understanding of independent assortment and crossing over. However, for the latter event, some candidates only mentioned the process without any comment on what it accomplished.
