What does homeostasis involve and how is this achieved? Explain.

For IB short answer questions, the command term is almost as important as the content of the subject itself. Here, "explain" highlights to you that an in depth answer with examples is required to get full mark. 

Homeostasis is the control of internal conditions within a system, for example blood glucose levels within in the human body. Homeostasis therefore involves maintenance of bodily conditions within their limits. Other examples are blood pH, water balance and ion concentrations within the cell and body temperature. Negative feedback is used to keep the balance of these different factors within the limit. Negative feedback systems often use the endocrine or nervous system. Within a negative feedback system, any significant deviation from a set point will trigger a stablising effect that will result in the opposite change from the initial deviation to return to the set point.