Question

Following are the examples of negative feedback system except:

• A. Body temperature regulation
• B. Blood glucose maintenance
• C. Blood clotting
• D. Blood pressure maintenance

Answer 1

The Correct Option is C

The correct option is (C): Blood pressure maintenance.

Answer 2

The question asks which process is NOT an example of negative feedback. In negative feedback, the body senses a change and acts to push the value back toward normal. Let's check each option.

1. Body temperature regulation: When body temperature rises or falls from the set point, the hypothalamus triggers sweating, shivering, or changes in blood vessel width to bring it back to normal. This corrects a deviation, so it is negative feedback.
2. Blood glucose maintenance: When blood sugar rises, insulin is released to lower it, and when it falls, glucagon is released to raise it, keeping glucose within a steady range. This is also negative feedback.
3. Blood clotting: Once a clot starts forming, activated platelets and clotting factors trigger the activation of even more clotting factors, amplifying the process rather than correcting it. This self-reinforcing cascade is a positive feedback mechanism, not negative feedback, which is why it is the exception here.
4. Blood pressure maintenance: Baroreceptors sense a rise or fall in blood pressure and trigger reflex changes in heart rate and blood vessel tone to bring pressure back to its normal range. This corrects a deviation, so it is negative feedback.

Three of the four processes work by correcting a deviation back toward a set point, while clot formation works by amplifying itself until the injury is sealed.

Therefore, the correct answer is Blood clotting.