The graph below shows how one factor in the internal environment in a person changes, and is returned to a normal level. If someone has a condition which makes their homeostatic system less responsive, how would the shape of the graph be altered?

Answer:

25) D

This is slightly tricky. It is important to realise which number indicates what.

1 on the graph indicates the change in internal environment.
2 indicates the point at which the response to the change is initiated.
3 indicates the time taken to bring the level back to normal.

Since someone has a condition which makes their homeostatic system less responsive, it would take longer for their system to start the response.

Hence, D is correct. 2 would be higher as the person’s homeostatic response would take longer to respond.