The diagram below represents the female reproductive system - NSC Life Sciences - Question 2 - 2023 - Paper 1

The process that takes place in part A is known as Fertilisation.

Fertilisation is the process in which the nucleus of the sperm fuses with the nucleus of the ovum. This union leads to the formation of a zygote.

Following fertilisation, the zygote begins to divide by mitosis, forming a solid ball of cells called the morula. The morula undergoes further division and develops into a hollow ball of cells known as the blastocyst. This blastocyst travels down the fallopian tube to the uterus, where it will implant into the thickened endometrium, which is prepared to provide nutrition and support to the developing embryo.

1. Part D, the vagina, is muscular and can expand, providing a protective environment as well as facilitating the passage of sperm.
2. The environment of the vagina is acidic, which helps to filter out non-viable sperm and provides a barrier against pathogens.

The prostate gland secretes an alkaline fluid that neutralizes the acidity of the vagina, creating a more hospitable environment for sperm and facilitating their survival during transit.