fertilisation

Question 1

What is required for fertilisation to occur?

Answer 1

Sperm must reach the egg, usually via sexual intercourse

Question 2

What is an erection?

Answer 2

Penis enlarged/firm due to blood flow

Question 3

What is ejaculation?

Answer 3

Contractions of ducts/glands expel semen (3mL; 250–300 million sperm)

Question 4

What does semen do in fertilisation?

Answer 4

Neutralises acidity of vagina/urethra and activates sperm

Question 5

What happens during female arousal?

Answer 5

Erectile tissue engorgement and mucous secretion for lubrication

Question 6

What is insemination?

Answer 6

Sperm released into vagina, travel through cervix/uterus to uterine tubes

Question 7

How many sperm typically reach the uterine tubes?

Answer 7

Only a few thousand out of hundreds of millions

Question 8

Where does fertilisation usually occur?

Answer 8

In the uterine tube

Question 9

At ovulation, what stage is the secondary oocyte in?

Answer 9

Metaphase II

Question 10

What is the corona radiata?

Answer 10

Outer follicle cells surrounding the oocyte

Question 11

What is the zona pellucida?

Answer 11

Glycoprotein matrix surrounding the plasma membrane of the oocyte

Question 12

What is the acrosomal reaction?

Answer 12

Sperm enzymes break down barriers so sperm can enter the oocyte

Question 13

What is the fertilisation membrane?

Answer 13

Membrane that forms to block more sperm from entering

Question 14

What happens after a sperm enters the egg?

Answer 14

Egg completes meiosis II, male and female pronuclei fuse, zygote formed

Question 15

Summary of fertilisation?

Answer 15

Sperm penetrates protective egg layers, pronuclei fuse, diploid zygote formed; many sperm needed due to high mortality and enzyme requirement