6.1 Exchange

Question 1

Explain what happens to SA:VOL as a cell becomes larger?

Answer 1

As organisms become larger their VOL increases out a faster rate then their SA

Question 2

Explain why cell size is limited?

Answer 2

Due to it allowing efficient exchange across their body surface

Question 3

Name 3 features of specialised exchange surfaces?

Answer 3

1. Larger SA relative to VOL of organism
2. Very thin so that the diffusion is short and rapid
3. A transport system to ensure the movement of the internal medium

Question 4

Define ficks law?

Answer 4

Diffusion= SA x difference in concentration/ length of diffusion path