Biology Revision Y8 2023
What is sperm?
Male gamete
What is an egg?
female gamete
Does a sperm cell have lots of mitochondria or not?
Lots of mitochondria
What is an acrosome?
part of the tip of the head of the sperm
What does an acrosome do?
releases enzymes to digest the egg membrane
Does a sperm cell have lots of cytoplasm or little?
Little
How many eggs released per month?
1
Do eggs contain cytoplasm or not?
Yes
Why do eggs contain cytoplasm?
as a food store for the developing fetus
What does the jelly coat on the egg do?
makes sure only one sperm can enter
Does the outer part of the egg soften or harden?
Harden
Why does the outer part of the egg cell harden after 1 sperm has entered?
to prevent other sperm from entering
External fertilisation?
Outside the body
where does external fertilisation usually occur?
in water
lots of eggs produced in external fertilisation?
yes
does external fertilisation increase or decrease chances of fertilisation?
Increase
lots or no aftercare in external fertilisation?
no aftercare
What can happen to externally fertilised eggs and sperm?
washed away/damaged/eaten
internal fertilisation?
inside the body
internal fertilisation usually occurs in?
mammals
in internal fertilisation are more or less eggs produced?
less
in internal fertilisation are sperm cells more or less likely to reach the egg cell?
more likely
What does the baby have a constant supply of in internal fertilisation?
nutrients and oxygen
Can many internally fertilised eggs be born at once?
No
Glands?
fluids that give sperm energy are released from here
Sperm ducts?
tube that sperm swims down from testes to urethra
Urethra?
tube that runs down centre of the penis
Penis?
Reproductive organ that enters vagina during internal fertilisation
Testes?
Sperm cells are made here
Foreskin?
protects head of penis
Scrotum?
Bag of skin that holds testes
Oviducts?
tube lined with cilia, moves egg to the uterus
Ovaries?
egg cells released from here
Uterus?
baby develops here
Cervix?
ring of muscle, base of uterus, holds baby in place
Vagina?
Baby moves here when being born