(a(i))[1]
The study indicates a $20\%$ chance that sexual intercourse three days before ovulation will lead to pregnancy. State how many times more likely pregnancy is if sexual intercourse happens two days later.
(a(ii))[5]
Explain the function of named hormones in the menstrual cycle during the days studied by this investigation.
(b)[3]
The diagram shows a fetus developing in the uterus of a pregnant human female. Name structure X and describe the functions of this structure.