4.1 Surface Area to Volume ratio

Question 1

why can gases diffuse directly into cells of small organisms?

Answer 1

short diffusion distance from outside + inside organs
large surface area to volume ratio
low metabolic demands

Question 2

if you have a high surface area to volume ratio, how does this affect the diffusion efficiency?

Answer 2

the higher the sa:v ratio, the more efficient the diffusion

Question 3

give two key facts about gas exchange in large organisms

Answer 3

have a small sa:v ratio- diffusion will not supply gas needs

have evolved specialised organs for gas exchange which each have a large sa:v ratio

Question 4

give 3 factors that affect rate of diffusion

Answer 4

surface area
concentration gradient
diffusion distance