B1.10 Exchanging materials

Question 1

What are the problems of having a small surface area to volume ratio?

Answer 1

Gases and food molecules can no longer reach every cell inside the organism by simple diffusion
Metabolic waste cannot be removed fast enough to avoid poisoning the cells

Question 2

How can the process of exchange be made more efficient?

Answer 2

Having a thin membrane
Large surface area to volume ratio
Efficient blood supply maintains a steep concentration gradient

Question 3

What is the alveoli?

Answer 3

Tin air sacs that move air into and out of your body

Question 4

How are the alveoli adapted?

Answer 4

Enormous surface area and have a very rich bloody supply

Question 5

How are the gills adapted?

Answer 5

They have a rich blood supply

Question 6

How does the fish get a constant flow of water over their gills?

Answer 6

They maintain concentrations needed for gas exchange - they get this by pumping water over the gills using a flap that covers the gills