3.3.1 | SURFACE AREA TO VOLUME RATIO

Question 1

describe the relationship between the size and structure of an organism and its surface area to volume ration

Answer 1

as size increases, SA:V tends to decrease
more thin/flat/folded/elongated structures increases SA:V

Question 2

how is SA:V calculated

Answer 2

divide surface area by volume

Question 3

suggest an advantage of calculating SA:mass for organism instead of SA:V

Answer 3

easier/quicker to find/more accurate because irregular shapes

Question 4

explain the relationship between SA:V and metabolic rate

Answer 4

as SA:V increases, metabolic rate increases because rate of heat loss per unity body mass increases so organisms need a high rate of respiration to release enough heat to maintain a constant body temperature

Question 4

what is metabolic rate and suggest how it can be measured

Answer 4

amount of energy used up by an organism within a given period of time
often measured by oxygen uptake as used in aerobic respiration to make ATP for energy release

Question 5

explain the adaptations that facilitate exchange as SA:V reduces in larger organisms

Answer 5

changes to body shape increases SA:V and reduces long diffusion distance/pathway
development of systems increases (internal) SA:V and reduces long diffusion distance/pathway, maintains a concentration gradient for diffusion