OCR A Level Biology A
OCR A Level Biology A Biological Membranes Exam Questions
Free OCR A Level Biology A exam questions on Biological Membranes, with mark schemes. Covers the fluid mosaic model, diffusion, osmosis, active transport and water potential.
Biological Membranes exam questions
1 question pack of real past exam questions with its mark scheme. Answer every question without notes, then mark your answers line by line against the mark scheme.
StemUp mark scheme flashcards
OCR A Level Biology A H420 Flashcards (Anki & Quizlet)
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Use them on Anki or Quizlet, then test yourself with the questions on this page.
From £10.99View flashcards
About OCR A Level Biology A Biological Membranes
This topic covers how substances cross membranes.
What you need to know
- Fluid mosaic model Phospholipid bilayer with proteins, cholesterol and glycoproteins.
- Passive transport Diffusion and facilitated diffusion through channels and carriers.
- Active transport Uses ATP and carrier proteins; endocytosis and exocytosis.
- Osmosis Movement of water down a water potential gradient.
Common mistakes in Biological Membranes
- Saying water moves to high water potential.
- Forgetting temperature affects membrane permeability.
- Calling osmosis active.
Try three Biological Membranes exam-style questions
1. Define water potential. (1 mark)
Show the mark scheme answer
The tendency of water to move out of a solution, measured in kPa.
2. Explain why red blood cells burst in pure water. (2 marks)
Show the mark scheme answer
Water enters by osmosis (1) and there is no cell wall to resist expansion (1).
3. State the role of cholesterol in membranes. (1 mark)
Show the mark scheme answer
It regulates fluidity.
Biological Membranes FAQs
What does Biological Membranes cover?
Membrane structure and transport.
Which practicals link here?
Beetroot permeability and osmosis in potato tissue.
Why is pure water 0 kPa?
It is the highest possible water potential.
Revise this topic with flashcards: OCR A Level Biology A H420 Flashcards, with mark scheme answers for Anki and Quizlet.
