A-level BIOLOGY 7402/3 Paper 3 Mark scheme June 2023

Question Marking Guidance Mark Comments

01.1

1. (There are) stretch-mediated sodium ion

channels (in the membrane);

2. (Increased pressure) deforms/changes

(sensory neurone/axon) membrane/lamella(e)

(Increased pressure) deforms/changes sodium

ion channels;

3. Sodium ion channels open;

4. Sodium ions diffuse in;

5. Depolarisation (leading to generator potential);

3 max

(3 x

AO1)

1. 2. 3. or 4. Accept

Na+

Max 2 if only

reference to sodium

and not sodium ions

4. Accept sodium

ions move in down

a concentration

gradient

5. Accept inside

becomes positive

No comments found.

jordancarter 7 months ago

This study guide is clear, well-organized, and covers all the essential topics. The explanations are concise, making complex concepts easier to understand. It could benefit from more practice questions, but overall, it's a great resource for efficient studying. Highly recommend!

A. You will receive a PDF that is available for instant download upon purchase. The document will be accessible to you at any time, from anywhere, and will remain available indefinitely through your profile.

A. Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

A. you are buying this document from us learnexams

A. No, you only buy these notes for $ indicated . You are not obligated to anything after your purchase.

A. check our reviews at trustpilot

Add To Cart

Buy Now