exam qs lqc 3

Question 1

Explain why many animals need a heart and a circulatory system.

Answer 1

heart is needed to pump blood around the body, mass flow, many animals have a small SA:V, circulatory system us needed to overcome limitations of diffusion, many animals have a high metabolic rate

Question 2

Explain why organisms need a mass transport system

Answer 2

to move molecules quickly between gas exchange surfaces and cells in organisms that have a small SA:V where diffusion would be inadequate