Exchange and SA:Vol

Question 1

Define diffusion

Answer 1

The movement of a substance down the concentration gradient

Question 2

Define osmosis

Answer 2

The movement of water down the water potential gradient across a semi-permeable membrane.

Question 3

Define passive transport

Answer 3

Transport that does not require energy to occur. E.g. Osmosis and Diffusion

Question 4

Define active transport

Answer 4

The movement of substances across a cell membrane, against the concentration gradient, and therefore requires energy.

Question 5

What correlates to high metabolism?

Answer 5

High SA:Vol, more energy is lost and used up.

Question 6

Why do large organisms have specialised exchanged system?

Answer 6

This is so the SA is increased as these animals will have a small SA:Vol.