B1.10 exchanging materials

Question 1

do single celled organisms have a large or small SA to V ratio and what does this mean

Answer 1

large SA to V ratio, so exchange of materials can happen easily

Question 2

do multicellular organisms have a large or small SA to V ratio and what does this mean

Answer 2

smaller SA to V ratio, so exchange is not easy so they nedd specialised exchange surfaces and transport systems.

Question 3

what must specialised exchange surfaces have

Answer 3

1. a large surface area
2. a thin membrane
3. (in animals) an efficient blood supply
4. (in animals, for gas exchange) ventilated