Surface Area to Volume Ratio

Question 1

explain the advantage of large organisms having specialised systems?

Answer 1

larger organisms have a smaller surface area to volume ratio
specialised system overcomes long diffusions pathway

Question 2

why do large organisms have mitochondria near the cell membrane?

Answer 2

-large organisms have a small surface area to volume ratio
-longer for oxygen to diffuse (to mitochondria)

Question 3

why do fish need a specialised system?

Answer 3

lower partial pressure of oxygen in water

Question 4

what do you do If there is a maths calculation

Answer 4

-show every calculation
(divide and multiply)
get 1 mark for working out

Question 5

why is the do the lungs have a bigger surface area to volume ration

Answer 5

more oxygen for aerobic repiration

Question 6

why do smaller organisms have a higher metabolic rate?

Answer 6

• smaller organisms have a larger surface area to volume ratio
  -loose more heat
• higher metabolic rate replaces this heat

Question 7

explain why oxygen uptake is a measure of metabolic rate?

Answer 7

• oxygen used in aerobic respiration which provides ATP which is used in metabolic processes