Question 4

Increased milk production by a feeding newborn demonstrates positive feedback.

Positive feedback occurs when a process is amplified or increased in response to a stimulus. In this case, the act of a newborn feeding stimulates the mother's body to produce more milk, thereby enhancing the feeding process.

A) Lowering blood sugar levels after a sweet snack

This option describes a negative feedback mechanism. When blood sugar levels rise after consuming sugar, the body responds by lowering those levels through insulin release. This is a classic example of negative feedback, where the response reduces the initial stimulus.

B) Shivering when the body is cold

Shivering is another example of negative feedback. It is the body's response to cold temperatures, aiming to generate heat and maintain body temperature. This mechanism counteracts the drop in temperature rather than amplifying it.

C) Retaining water after heavy exercise

Retaining water after heavy exercise can be considered a response to dehydration, which is part of a negative feedback system. The body conserves water to restore balance, counteracting the loss of fluids rather than enhancing any process.

D) Increased milk production by a feeding newborn

This option exemplifies positive feedback as the act of the newborn suckling stimulates further milk production. The more the baby feeds, the more milk is produced, resulting in an amplified response that supports the ongoing need for feeding.

Conclusion

The correct answer, increased milk production by a feeding newborn, is a clear example of positive feedback, where the system is enhanced rather than regulated. In contrast, all other options illustrate negative feedback mechanisms aimed at restoring balance in the body. This distinction is crucial for understanding how different biological processes operate.