Maintenance of a consistent body temperature
i. In bright sunlight, the Calvin cycle takes place in the stroma. At the time of the Calvin cycle, the products of the light-dependent reactants, that is, ATP and NADPH are used to transform molecules of carbon dioxide into high-energy sugars.
ii. In the darkness, the Calvin cycle also takes place in the stroma. During the Calvin cycle, the products of the light-dependent reactions, that is, ATP and NADPH are used to transform the molecules of carbon dioxide into high-energy sugars.
iii. If the plant has been kept in dark for an extended period of time, then there may be not enough production of ATP and NADPH taking place in order to continue the Calvin cycle.
According to model 3. During the child birth the stimulus is baby pushes against the cervix and the response would be hypothalamus oxytocin to male uterine walls contract.
Explanation:
The first contractions of the stimulus (labor) pushes the baby towards the cervix that is the lowest part of the uterus. Normal childbirth is done by positive loop. A positive feedback loop is the change in body status than a return to homeostasis.
One of the best example for positive feedback system is child birth. During labor, a hormone called oxytocin is released which intensifies and speeds up contractions.
Child birth will eventually stop the stimulus and stop the child birth feed back loop.
The answer of this question is C.