B1.10 Exchanging materials

Question 1

What is the surface area to volume ratio?

Answer 1

The SA to V ratio is bigger when the size of the organism is smaller but if the organism is bigger then the SA to V ratio will be smaller

Question 2

Why can’t gases and food molecules reach every cell inside the organisms by simple diffusion?

Answer 2

Due to the surface area to volume ratio

Question 3

Why do single celled organisms have a relatively large SA to V ratio?

Answer 3

So all necessary exchanges can take place over this surface

Question 4

What do exchange surfaces usually consist of?

Answer 4

A large surface are, thin walls which give short diffusion didtances

Question 5

What adaptation do multicellular organisms have

Answer 5

Many organs are specialised with effective exchange surfaces