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1. What is homeostasis and why is it important for the human body? (2
marks)
Homeostasis is the process of maintaining a stable internal environment
despite changes in the external environment. It is important for the human
body because it allows the cells and organs to function optimally and
prevents damage or disease.
2. What are the three components of a homeostatic control system? (3
marks)
The three components of a homeostatic control system are a sensor, a
control center, and an effector. The sensor detects changes in a variable,
such as temperature or blood pressure. The control center compares the
sensor input with a set point and sends signals to the effector. The effector
responds to the signals and restores the variable to the set point.
3. What is negative feedback and give an example of a negative feedback
loop in the human body? (3 marks)
Negative feedback is a mechanism that reverses or opposes a change in a
variable to maintain homeostasis. An example of a negative feedback loop
in the human body is the regulation of blood glucose levels by insulin and
glucagon. When blood glucose levels rise, the pancreas secretes insulin,
which stimulates cells to take up glucose and lowers blood glucose levels.
When blood glucose levels fall, the pancreas secretes glucagon, which
stimulates the liver to release glucose and raises blood glucose levels.
4. What is positive feedback and give an example of a positive feedback
loop in the human body? (3 marks)
Positive feedback is a mechanism that amplifies or reinforces a change in
a variable to move away from homeostasis. An example of a positiveÂ
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