The need for Homeostasis 5.1.1

Question 1

What is the need for communication systems in organisms?

Answer 1

In order to function properly and efficiently, they have communication systems that ensure their internal conditions are kept relatively constant.

Question 2

What are two communication systems in mammals that contribute to homeostasis?

Answer 2

• The nervous system
• The endocrine system

Question 3

Give 4 physiological factors that are controlled by homeostasis in mammals

Answer 3

• Blood pH
• Blood glucose concentration
• Core body temperature
• Water potential of the blood

Question 4

Define homeostasis

Answer 4

The maintenance of a constant internal environment

Question 5

Why do we need a stable core temperature and blood pH?

Answer 5

Vital for enzyme activity
- Enzymes are denatured at extremes of pH and temperature, as hydrogen/ionic bonds will break which alters the shape of the active site and therefore enzyme-substrate complexes can no longer form

Question 6

What happens if blood glucose concentration is too high?

Answer 6

The water potential of the blood will be altered

Question 7

Give an example of how plants carry out homeostasis

Answer 7

Stomata control the diffusion of gases in and out of the leaves - which is controlled by guard cells