Exchange Surfaces

Question 1

In what size organisms can exchange take place over the surface of the body?

Answer 1

Small

Question 2

What are the three main factors that affect the need for an exchange system?

Answer 2

Size
Surface area to volume ratio
Level of activity

Question 3

How does size affect the need for an exchange system?

Answer 3

If small enough diffusion will supply enough oxygen and nutrients for the cells o remain active.
If larger an exchange system is needed as the diffusion pathway is too long

Question 4

How does surface area to volume ration affect the need for an exchange system?

Answer 4

If an organism has a large surface area to volume ration they are able to diffuse in the oxygen and nutrients they need.

Question 5

What advantage does the flat worm have?

Answer 5

It has a large surface area to volume ratio, a great SA for exchange.

Question 6

What does metabolic activity use?

Answer 6

Food and requires oxygen to release the energy in aerobic respiration.

Question 7

What does a large surface area provide?

Answer 7

More space for molecules to pass through

Question 8

What does having a thin barrier reduce?

Answer 8

The diffusion distance for the oxygen and nutrients.

Question 9

What adaption do the alveoli have to increase exchange?

Answer 9

The walls of the alveoli are only one cell thick and permeable to the substances they exchange.

Question 10

How does a fresh blood supply assist with the rate of exchange?

Answer 10

It keeps the concentration of molecules high so that the molecules are able to move in the concentration gradient easier.