3.1 Surface area to volume ratio

Question 1

How does an organisms size relate to their surface area to volume ratio?

Answer 1

The larger the organisms, the lower the surface area to volume ratio

Question 2

How does an organisms surface area to volume ratio relate to their metabolic rate?

Answer 2

The smaller the surface area to volume ration, the higher the metabolic rate

Question 3

How might a large organism adapt to compensate for its small surface area to volume ratio?

Answer 3

Changes that increase surface area e.g. folding; body parts become larger e.g. elephants ears; elongating shape; developing a specialised gas exchange surface

Question 4

Why do multicellular organisms require specialised gas exchange surfaces?

Answer 4

Their smaller surface area to volume ratio means the distance that needs to be crossed is larger and substances cannot easily enter the cells as in a single-celled organism