Module 5: Communication and Homeostatsis

Question 1

Need for communication system

Answer 1

To changes in external and internal environments as cellular activities rely on enzymes which require a specific set of conditions to work effectively

Question 2

Differences between receptor cells and effector cells

Answer 2

Receptor cells monitor and detect changes in the environment whereas effector cells bring about a response

Question 3

Difference between negative and positive feedback

Answer 3

Negative feedback is a mechanism where effectors reverses a change, bring the system back to optimum. Positive feedback is a mechanism where effectors reinforce change, taking the system further away from the optimum.

Question 4

Physiological and behavioural responses in endotherms

Answer 4

Physiological
Vasoconstriction and increased metabolism when too cold
Vasodilation and sweating when too hot
Behavioural
eat more and hibernate during cold periods
breathe more and shelter from the sun in hot periods

Question 5

Behavioural responses in ectotherms

Answer 5

Expose body to sun, raise hairs and shiver to warm up

Hide from sun and reduce body surface exposed to sun