Practice Question

1.Explain why diffusion is slower in multicellular organisms compared to single celled organisms

Smaller surface area to volume ratio

There are multiple cell layers deep, this increases the diffusion distance

2. State the names of two exchange surfaces in plants

Root hair cell

Spongy mesophyll cell

(There can be other answers, but they must have a large surface area or short diffusion distance)

3. How are exchange surfaces adapted for their role in diffusion.

1.Large Surface area

2.Thin to provide short diffusion pathway