Homeostasis And Response- B5- Paper 2

Question 1

What is homeostasis?

Answer 1

Homeostasis is your body’s control of enzymes. When they’re found to be to high they’re lowered and when they’re found to be too low they’re heightened.

Question 2

Negative feedback pathway (too high)

Answer 2

1. Receptor- detects stimulus is too high
2. Co-ordination centre- receives the message and organises a response
3. Effector- produces a response to counteract and restore optimum levels
4. The levels decrease

Question 3

Negertive feedback pathway (too low)

Answer 3

1. Receptor- detects stimulus is too low
2. Coordination centre- receives message and organises a response
3. Effector- produces a response to counteract and restore to optimum levels
4. Levels increase

Question 4

Why do the internal conditions of your body need to be regulated? [1 mark]

Answer 4

To maintain the right conditions for cells to function properly and for enzyme reactions.

Question 5

Why will someone lose more water from their body when running a marathon on a hot day? (1 mark)

Answer 5

If a person is running a marathon on a hot day they are likely to sweat more often in order to help them cool down. This means they will lose more water from their body.

Question 6

Why is it important to keep your body temperature at the correct temperature?

Answer 6

If it gets too high, the enzymes become denatured and can no longer work properly and the body’s metabolism is disrupted.
If it gets too low, than the metabolic process occurs too slowly.

Question 7

Describe the main difference between hormonal coordination and nervous coordination. (3 marks)

Answer 7

• Hormones involve chemical messages wheras nervous impulses rely on electrical impulses.
• nervous impulses are faster acting compared to hormones which are slower.
• hormones are selected by glands and travel in the blood whereas nervous impulses travel along neurones.