3.3.1 Surface area to volume ratio

Question 1

why is SA: V significant?

Answer 1

the relationship between the size of an organism or structure and its SA: V plays a role in the types of adaptations an organism will have

Question 2

characteristics of SA: V in small organisms

Answer 2

• large surface area to volume ratio
• means that there is a big surface for the exchange of substances
• there is also a smaller distance from the outside of the organism to the middle of it
• therefore, small organisms can simply exchange substances across their surfaces

Question 3

characteristics of SA: V in small organisms

Answer 3

• the larger an organism, the smaller the SA: V
• will typically have a higher metabolic rate, which demands efficient transport of waste out of cells and reactants into cells
• as a result, they have adaptations that help make exchange across surfaces more efficient

Question 4

examples of adaptations to increase SA: V

Answer 4

• villi and microvilli
• alveoli and bronchioles
• spiracles and tracheoles
• gill filaments and lamellae
• thin wide leaves
• many capillaries