Fertilisation Flashcards
1
Q
When and where does fertilisation occur?
A
- in the outer third of the fallopian tube
- when the nuclei of the sperm and egg fuse to form a zygote
2
Q
What happens after semen is deposited in the vagina?
A
- sperm move through the cervix, uterus and into the fallopian tubes until they reach the egg
3
Q
What happens to the egg during fertilisation?
A
- the egg, surrounded by follicle cells, is sucked into the fallopian tube by action of the fimbriae
4
Q
What happens during step 1 of fertilisation?
A
- thousands of sperm surround the egg
5
Q
What happens during step 2 of fertilisation?
A
- hydrolytic enzymes, released from the acrosomes, break down the follicle cells
6
Q
What happens during step 3 of fertilisation?
A
- only one sperm penetrates the membrane of the egg; the tail is discarded
7
Q
What happens during step 4 of fertilisation?
A
- the nuclei of the sperm and egg fuse, forming a diploid zygote
8
Q
What happens during step 5 of fertilisation?
A
- a fertilisation (egg) membrane forms immediately, which prevents other sperm from entering the egg