Spermatogenesis, Oogenesis And Fertilisation

Question 1

Describe the processes of spermatogenesis and spermiogenesis including appropriate hormonal influences

Answer 1

Spermatogenesis: the process of the formation of male gametes in testes (sperm)
In early foetal development primordial germ cells differentiate into spermatogonia, which remain dormant until puberty
FHS from anterior pituitary stimulates sperm production
Spermiogenesis is a stage of spermatogenesis where the spermatic develops into a mature spermatozoon. It is comprised of 4 phases.
1) Golgi phase
2) cap phase
3) tail phase
4) maturation phase

Question 2

Describe the spermatozoon including the individual structure and function of each part

Answer 2

A mature spermatozoon has a head, a body, and a long whip-like tail used for motility
The head is almost completely filled by the nucleus, containing its DNA. It also contains the enzymes required to penetrate the outer layers of the ovum to reach, and fuse with its nucleus
The body is packed with mitochondria, to fuel the propelling action of the tail that powers it along the female reproductive tract

Question 3

Describe the process of oogenesis including appropriate hormonal influences

Answer 3

Oogenesis is the growth process in which the primary egg cell (or ovum) becomes a mature ovum
The egg cell remains as a primary ovum until the time for its release from the ovary arrives. The egg then undergoes cell division
The nucleus splits in half to half of its chromosomes go to one cell and half to another. The larger one is known as the secondary ovum.
This grows in the ovary until it reaches maturation; it then breaks loose and travels into the Fallopian tubes. It is then suitable for fertilisation.

Question 4

Discuss the process of fertilisation

Answer 4

Sperm deposition
Capacitation- the change sperm undergo in the female reproductive tract that enables them to penetrate and fertilise an ovum
Fusion of sperm cell membrane with oocyte membrane
Oocyte completes meiosis 2- becomes ovum
Game fusion- becomes a zygote

Question 5

Describe the process of implantation

Answer 5

It undergoes fertilisation
The blastocyst then burrows into the uterine lining