Gametes And Fertilisation

Question 1

What is size of egg and sperm

Answer 1

Egg is 100um and sperm is 5um

Question 2

Why is egg so large

Answer 2

Egg is large because it contains lots of lipid droplets which provide energy for cell division and it increases chance of fertilisation as more sperm can attach.

Question 3

What does the cell membrane have in egg

Answer 3

Cell membrane in egg has receptors which are complementary to the receptors in the sperm head to fit together, which allows them to attach to each other.

Question 4

Haploid nucleus and why it is important

Answer 4

Haploid nucleus contains 23 chromosomes. It needs to have half so diploid number is restored

Question 5

What are lysosomes known as

Answer 5

Lysosomes are known as cortical granules.

Question 6

Zona pelucida

Answer 6

Zona pelucida is jelly like coating around the cell membrane

Question 7

Why do sperm only go to egg

Answer 7

Egg releases chemical which are detected by receptors in sperm so Sperm can find it

Question 8

Middle part of sperm and it’s function

Answer 8

Middle of sperm there are many mitochondria which carry out aerobic respiration to provide ATP so sperm can swim to egg

Question 9

What is in sperm head

Answer 9

There is a haploid nucleus in sperm head and during fertilisation diploid number is restored.

Question 10

Acrosome

Answer 10

Acrosome is a specialised lysosome contains acrosin

Question 11

Adaptations of sperm

Answer 11

Streamlined so there is less resistance while swimming
Acrosome to penetrate the outer layer of egg
Lots of mitochondria to provide energy for sperm to swim
Flagellum so it can swim
Receptors on membrane so it can bind to receptors on egg