3.1: Surface area to volume ratio

Question 1

Why can small organisms simply exchange substances across surfaces?

Answer 1

Large surface area to volume ratio - smaller distance from outside to middle of organism

Question 2

Adaptations to increase surface area:volume

Answer 2

1) Villi and microvilli - absorption of digested food

2) Alveoli and bronchioles - gas exchange

3) Spiracles and tracheoles - Gas exchange

4) Gil filaments and lamellae -gas exchange

5) Thin wide leaves - Gas exchange

6) Many capillaries - Capillary network

Question 3

Why do large organisms have adaptations to increase surface area?

Answer 3

To overcome small surface area to volume ratio