For a woman to become pregnant, a sperm must fertilise an egg around the time of ovulation. Around the time of ovulation, her basal body temperature rises slightly.
A woman who wanted to become pregnant tracked her body temperature every morning for 28 days, starting on the first day of her menstrual cycle. Her daily readings are shown in the table below:
| Day | Temperature (∘C^\circ\text{C}∘C) | Day | Temperature (∘C^\circ\text{C}∘C) |
|---|---|---|---|
| 1 | 36.6 | 15 | 36.9 |
| 2 | 36.6 | 16 | 37.0 |
| 3 | 36.5 | 17 | 37.0 |
| 4 | 36.6 | 18 | 37.0 |
| 5 | 36.5 | 19 | 36.9 |
| 6 | 36.6 | 20 | 36.9 |
| 7 | 36.5 | 21 | 36.9 |
| 8 | 36.6 | 22 | 36.9 |
| 9 | 36.6 | 23 | 36.9 |
| 10 | 36.6 | 24 | 36.9 |
| 11 | 36.5 | 25 | 36.9 |
| 12 | 36.6 | 26 | 36.9 |
| 13 | 36.9 | 27 | 36.8 |
| 14 | 36.9 | 28 | 36.6 |
What was the total number of days that her body temperature was strictly below 36.8∘C36.8^\circ\text{C}36.8∘C?
On which day was an egg most likely released from her ovary?
Suggest how the woman could ensure her body temperature measurements are as accurate and consistent as possible.
During the 28 days, the ovaries of the woman released two different hormones, X and Y. The table below outlines some of the roles of these hormones:
| Hormone X | Hormone Y |
|---|---|
| Repairs and thickens the uterus lining | Maintains the uterus lining |
| Responsible for female secondary sexual characteristics | Prevents further release of eggs |
Name Hormone X.
Name Hormone Y.
State the pathway by which these hormones travel from the ovaries to the uterus.
State two female secondary sexual characteristics that develop during puberty, other than the start of the menstrual cycle.
43 exam-style questions on Edexcel IGCSE Biology Reproduction. Each one has a worked solution and a mark scheme showing where the marks go.