CAPE Biology Unit 1 · 2014 · Paper 1 · Question Q39

Item 39 refers to the following diagram which shows the changes in the levels of the ovarian hormones which regulate the human menstrual cycle. Which of the following BEST describes the events highlighted by the arrows labelled X and Y? \begin{tabular}{|l|l|l|} \hline & \multicolumn{1}{c|}{\textbf{X}} & \multicolumn{1}{c|}{\textbf{Y}} \\ \hline (A) & Increasing levels of oestrogen promote thickening of the endometrium. & Increasing levels of progesterone prepare the endometrium for implantation of a fertilized ovum. \\ \hline (B) & Increasing levels of LH promote thickening of the endometrium. & A surge in FSH concentration prepares the endometrium for implantation of the fertilized ovum. \\ \hline (C) & Increasing levels of progesterone promote thickening of the endometrium. & A surge in LH concentration prepares the endometrium for implantation of a fertilized ovum. \\ \hline (D) & Increasing levels of FSH promote thickening of the endometrium. & Increasing levels of oestrogen prepare the endometrium for implantation of a fertilized ovum. \\ \hline \end{tabular}

1. (A)X: Increasing levels of oestrogen promote thickening of the endometrium.; Y: Increasing levels of progesterone prepare the endometrium for implantation of a fertilized ovum.
2. (B)X: Increasing levels of LH promote thickening of the endometrium.; Y: A surge in FSH concentration prepares the endometrium for implantation of the fertilized ovum.
3. (C)X: Increasing levels of progesterone promote thickening of the endometrium.; Y: A surge in LH concentration prepares the endometrium for implantation of a fertilized ovum.
4. (D)X: Increasing levels of FSH promote thickening of the endometrium.; Y: Increasing levels of oestrogen prepare the endometrium for implantation of a fertilized ovum.

This question uses a figure or table from the paper — you'll see it when you practise.