3.3.1 surface area : volume

Question 1

why are single-celled organisms able to perform exchange via their surface

Answer 1

large sa:v
short diffusion distance

Question 2

why are multicellular organisms unable to perform exchange via their surfaces

Answer 2

small sa:v
large diffusion distance
impermeable surface

Question 3

why does a small mammal need a high metabolic rate

Answer 3

small mammals have a high SA:V, heat is lost easily, high metabolic rate needed to generate enough heat to maintain a constant body temp

Question 4

how is an organisms size relative to their SA:V

Answer 4

smaller organisms have a greater SA:V
larger organism had a smaller SA:V

Question 5

features of exchange surfaces

Answer 5

large surface area
small diffusion distance
maintaining a steep concentration gradient