Exam 1 - Fertilization

Question 1

Capacitation

Answer 1

Sperm activation from a dormant state

Question 2

How long does capacitation take to occur?

Answer 2

2-3 hours

Question 3

What occurs before capacitation?

Answer 3

Sperm just move around randomly from areas of high concentration to areas of low concentration

Question 4

What 3 things occur during capacitation?

Answer 4

1. ATP production
2. Flagellum movement - for up to 48 hrs
3. loss of a “coat” which hides egg-binding proteins/receptors

Question 5

How is capactiation induced?

Answer 5

By substances in the vagina

Question 6

How is the sperm aided toward the egg (recently released from ovary) after capacitation?

Answer 6

Via smooth muscle contractions and cilia of the oviducts

Question 7

Why are sperm attracted to move toward the egg once inside the oviduct?

Answer 7

Chemotaxis, they are attracted to a chemical signals produced by the eggs

Question 8

Which part of the ovulated egg releases chemical signals?

Answer 8

The granulosa cells or the fluid in the follicular antrum

Question 9

Why is it important for different species of eggs to release different chemicals?

Answer 9

In order to ensure that fertilization does not occur across species

Question 10

Roughly how many sperm will reach the egg in an attempt to fertilize it

Answer 10

approx. 100

Question 11

PH20 enzyme

Answer 11

Located on the head of sperm it digest the ECM between the granulosa cells surrounding the egg