Final answer:
The correct analogy is hunger is to satiety as ghrelin is to cholecystokinin, with ghrelin stimulating hunger and cholecystokinin inducing satiety. While leptin is also a satiety hormone, it is not the correct answer in this sequence, as it is secreted by fat cells and it regulates appetite by signaling the brain to decrease hunger when fat stores are sufficient.
Step-by-step explanation:
Hunger is to satiety as ghrelin is to cholecystokinin. Ghrelin is known as the 'hunger hormone' because it stimulates appetite, increases food intake, and promotes fat storage. Cholecystokinin, on the other hand, is a hormone that induces satiation by slowing down gastric emptying and stimulating the digestion of fat and protein. While leptin is also a satiety hormone, it is not the correct answer in this sequence, as it is secreted by fat cells and it regulates appetite by signaling the brain to decrease hunger when fat stores are sufficient.