How does the combined contraceptive pill prevent pregnancy?

It contains oestrogen and progesterone, which inhibit the release of FSH so no egg matures in the ovary.

Give one advantage and one disadvantage of using the contraceptive pill.

It is more than 99% effective when taken correctly, but it can cause side effects such as headaches and raised blood pressure and gives no protection against sexually transmitted infections.

How does a condom prevent pregnancy?

It acts as a barrier that stops the sperm reaching the egg.

Give two advantages of barrier methods over hormonal methods of contraception.

They also protect against sexually transmitted infections and they have no hormonal side effects.

What is sterilisation, and why does it suit only some people?

The sperm ducts or the oviducts are cut or tied so gametes can never meet; it is meant to be permanent and is very difficult to reverse.

OCR GCSE Biology A J247

Cell Level Systems

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Organism Level Systems

Methods of contraception

3 things to know
Paper 1

Overview

How the combined pill, other hormonal methods, condoms and other barrier methods prevent pregnancy, the advantages and disadvantages of each, sterilisation, why natural methods are less reliable, and which methods are the most effective.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

Why are natural methods that avoid intercourse near the time of ovulation less reliable?

Key term

Name three hormonal methods of contraception other than the pill.

Key term

Which methods of contraception are the most effective, and how do condoms compare?

Questions from this subtopic

Each one with the model answer underneath.

1
How does the combined contraceptive pill prevent pregnancy?
Model answer
It contains oestrogen and progesterone, which inhibit the release of FSH so no egg matures in the ovary.
2
Name three hormonal methods of contraception other than the pill.
Model answer
The contraceptive implant, the contraceptive injection and the skin patch.
3
Give one advantage and one disadvantage of using the contraceptive pill.
Model answer
It is more than 99% effective when taken correctly, but it can cause side effects such as headaches and raised blood pressure and gives no protection against sexually transmitted infections.
4
How does a condom prevent pregnancy?
Model answer
It acts as a barrier that stops the sperm reaching the egg.
5
Give two advantages of barrier methods over hormonal methods of contraception.
Model answer
They also protect against sexually transmitted infections and they have no hormonal side effects.
6
What is sterilisation, and why does it suit only some people?
Model answer
The sperm ducts or the oviducts are cut or tied so gametes can never meet; it is meant to be permanent and is very difficult to reverse.

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