Exchange surfaces intro

Question 1

What is the need for exchange surfaces? (3 main points)

Answer 1

Organisms must take in food,oxygen and water, and other essential substances, from the environment.

Plants also need carbon dioxide for photosynthesis.

Organisms also need to remove waste substances.

Question 2

What 2 features arise from specialised exchange surfaces?

Answer 2

• Organism size
• Surface area to Volume ratio

Question 3

What about single cell organisms show that they do not need a specialised exchange surface system?

Answer 3

• Larger SA/vol ratio making the diffusion distance longer
• multiple layers of cells so it slows the rate of diffusion

-they need constant/efficient gas exchange of O2 to CO2

Question 4

Features of an efficient gas exchange system?

Answer 4

• large surface area
• thin (efficient diffusion)
• good blood supply & ventilation