gas exchange of small organisms

Question 1

what happens when you increase the volume

Answer 1

• less oxygen can diffuse as it will be used up by the outer cells before it reaches the inner cells

Question 2

what impact does level o activity have on gaseous exchange

Answer 2

• if animals are more active, they need more volumes of oxygen

Question 3

explain the gas exchange system in an amoeba

Answer 3

• very small
• thin
• large surface area with an irregular shape
  -simple diffusion of oxygen from the air into the organism

Question 4

explain the gas exchange system in a flatworm

Answer 4

• very thin
• large surface area
• small diffusion pathway as no cell is too far from the surface of the organism
• relies on simple diffusion

Question 5

explain the gas exchange system of an earthworm

Answer 5

• folding skin providing a large total surface area
• basic circulatory system with haemoglobin
• habitats have high humidity to reduce water lost by the organism