Section E: Attempt the following case study question.
 
On every 28 days, a single egg is released from either of the two ovaries during the menstrual cycle, which is a cycle of events in the female reproductive organs.  

This is controlled by sex hormones. A married woman's regular menstrual cycle ended suddenly, and she was pleased to be expecting her first child after getting tested.
 
 
a. Why menstruation stops in a pregnant woman?
 
During pregnancy, the levels of the hormones such as and will be elevated. This will halt the subsequent menstrual cycle, preventing a pregnant lady from experiencing menstruation.
 
b. Arrange the correct sequence of events that leads to pregnancy.

i. Implantation
ii. Ovulation
iii. Fertilisation
iv. Zygote formation

The correct sequence is ___________

           
c. Differentiate between a zygote and an embryo.
 
Zygote has cell/cells formed from the The embryo has cell/cells formed from .
 
d. What changes occur in the uterus during pregnancy?
 
If the fertilization has done, occurs. The corpus luteum grows.