ML Lecture Question’s:

Question 1

What are examples of detectors used by vertebrate animals?

Answer 1

Blood glucose, oxygen, senses

Question 2

Explain how the effects of dehydration can be counter-acted by a physiological and behavioural response, acting through negative feedback:

Answer 2

Behavioural response: Drinking water and staying out of the sun
Physiological: Negative feedback = water re-absorption in the kidneys in response to aldosterone and anti-diuretic hormones (both through their own respective pathways)

Question 3

Explain the concept of homeostasis:

Answer 3

Homeostasis deals with the concept as initially proposed by Bernard and Cannon: maintenance on a constant environment by keeping the values for a variable between two set point.

Question 4

How does homeostasis differ from allostasis?

Answer 4

Not all set points are fixed. Allostasis allows for a concept where set points can be adjusted e.g., Habituation and acclimatisation

Question 5

List the organelles in an animal cell

Question 6

What is signal transduction? Why is it important?

Answer 6

The activation of the receptor needs to results in a change in the function of the cell. Thus, the signal (hormone) upon binding to the receptor needs to activate an intracellular cascade (2nd messengers such as cAMP) that can then bring about change in cell function (directly or indirectly)

Question 7

How can different tissues in the body respond differently to the same signal (ligand)?

Answer 7

This allows for the signal to be connected to different intracellular cascades, and therefore, to bring about a different response

Question 8

Contrast the series of events leading to a change in cell function by a hormone that binds to an intracellular receptor and one that binds to a membrane receptor: