Fertilisation

Question 1

What is the structure of the sperm and what does the prostate gland do ?

Answer 1

1. The sperm contains nucleus which is in the head, acrosome, midpiece (mitochondria) and tail
2. The prostate glands act on the smooth muscles of the urterus causing it to contract backwards

Question 2

What does the coagulation enzymes do?

Answer 2

1. coagulation enzymes coagulate the testisular and vaginal fluids allowing the sperm cells to bind to the wall of the vagina, ones that didnt bind become lost
2. The coagulation is broken up and the sperm can be released with relaxin for speed to go through the fallopan tube and fertilise the egg

Question 3

What happens in the capacition reaction?

Answer 3

1.Estrogen release cervial fluids which help the capacition
2.Capacition washes off the proteins and chlorestol so it is just left with modified glycoproteins
3.Capaction increases the mobility of the sperm

Question 4

What happens in the acrosomal reaction?

Answer 4

1.The sperm has a protein which recoginses the 2 zona pellcida receptors and allow the sperm to bind to it
2.The head of the sperm opens and the acrosome fuses and releases acrosina and protease, this causes a hole in the zona pellcida

Question 5

What happens in the fast block polyspermy?

Answer 5

1. The sperm goes to the cell memebrane of the oocyte and bind with the beta protein which allows channels to open and let na+ leave
2. The Na+ ions make it positive and blocks the other sperms then the alpha binds with the sperm
3. The sperm cell membrane and the oocyte cell memebrane fuse together releasing genetic material into the egg

Question 6

What happens in the slow to block polyspermy?

Answer 6

1. The nucleus in the egg activates the SER to release calcium which activate sthe lyosomes to move and fuse
2. The enzyme in the lysosome are releases and they break down the zona pellcida and cause the cell membrane to be hard
3. The female 23 + make 23+ 46 chromosome + zygote