OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Get ready for the OCR GCSE Biology exam with our comprehensive quiz, featuring flashcards and multiple choice questions. Understand the exam format, key topics, and effective study strategies to excel.

Start Multiple Choice Practice Test
Start Flash Cards

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

What does the Intrauterine System (IUS) primarily do to prevent pregnancy?

  1. Thickens the cervical mucus

  2. Thins the lining of the uterus

  3. Increases ovulation

  4. Inhibits FSH production

The correct answer is: Thins the lining of the uterus

The Intrauterine System (IUS) primarily works by thickening the cervical mucus, which serves to block sperm from entering the uterus. This increased thickness creates a barrier that makes it difficult for sperm to reach any egg that may have been released, thus preventing fertilization. In addition to this, the IUS also affects the lining of the uterus by thinning it. A thinner lining is less conducive to implantation of a fertilized egg, further reducing the chances of pregnancy. This method of action is highly effective in contraception. The options related to increasing ovulation or inhibiting FSH production are not accurate descriptions of how the IUS functions. Instead, the IUS aims to create a hostile environment for sperm and implantation, ensuring greater efficacy as a contraceptive method.

More Questions Like This