AP BIOLOGY

Detailed explanation-1: -The ripening process in fruits involves the hormone ethylene and it is an example of a positive feedback mechanism.

Detailed explanation-2: -Positive feedback mechanisms are rare. It amplifies changes rather than reversing them. The release of oxytocin from the posterior pituitary gland during labor is an example of positive feedback mechanism. Oxytocin stimulates the muscle contractions that push the baby through the birth canal.

Detailed explanation-3: -Positive feedback loop-A feedback loop where the product will amplify the system is considered a positive feedback loop. For example, the ripening of fruits, i.e. when one fruit on a tree ripens it releases ethylene which then stimulates the ripening of other fruits as well.

Detailed explanation-4: -A vegetation positive-feedback switch is a process in which a community modifies the environment, making it more suitable for that community.