Gametes and Fertilisation

Question 1

Gametes

Answer 1

Gametes are male and female sex cells, they join together to form a zygote.
Gametes contain half the numbers of chromosome

Question 2

How fertilisation may occur

Answer 2

sperm swim towards the egg cells
once the sperm cell makes contact with the zono pellucida acrosomal reaction.
The sperm head fuses with the cell membrane of the egg cell. This triggers cortical reaction,
This makes sures that only one sperms fertilises the egg cell. only the sperm nucleus enters the egg cell.
The nucleus of the sperm cell fuses with the nucleus of the egg cell

Question 3

acrosmal reaction

Answer 3

sperm swims next to the egg. One sperm is in contact with the zono pellucida of the egg, the acrosomal reaction occurs where the digestive enzyme are released from the acrosome of the sperm, these enzymes digest the zono pellucida, so the sperm can through it to cell membrane of the egg cell

Question 4

cortical reaction

Answer 4

sperm fuses with the cell membrane of the egg, which triggers the cortical reaction. The egg cell releases the contents of vesicles called cortical granules into the space between the cell membrane and the zono pellucida. The chemical from the cortical granules makes the zono pellucida thivker, which makes it inpenetrable to other sperm. This makes sure that only one sperm fertillises the egg cell