3.1 Exchange Surfaces

Question 1

What are the three main factors that affect the need for an exchange system?

Answer 1

The size
Surface area to volume ratio
Level of activity

Question 2

Why won’t small organisms need a specialised exchange system?

Answer 2

All the cytoplasm is very close to the environment in which they live.
Diffusion with supply enough oxygen and nutrients to keep them alive and active

Question 3

Why will multicellular organisms need a specialised exchange system?

Answer 3

They have several layers of cells so there will be a longer diffusion pathway for oxygen and nutrients diffusing in from the outside. Diffusion is too slow to be sufficient for the innermost cells

Question 4

What are the three main features of a good exchange system?

Answer 4

-large surface area
-a good blood supply
-a thin permeable barrier to reduce the diffusion distance

Question 5

What is cartilage