The doctor is recommending the intake of a serotonin agonist that will activate the <span>5-HT receptors. There are several agonists for these receptors being </span>Lorcaserin one of the most used ones in <span>weight-loss</span>, which is a selective agonist for

receptors.
Answer:
A. Codominance
Explanation:
Codominance is where both traits show, and in this case, with the red and blue, they show. Incomplete dominance is characterized by blending; in that case, the fish would have to be purple because red and blue make purple. It's not multiple alleles because there isn't anything to suggest that there are more than 2 alleles for the color gene.
An elephant's trunk evolved in order to be able to stuff in and eat as much food as it can to become the big animal it is today.
The elephant's ancestors were small and had a short nose. As it turns out, the larger body size the elephant has, the more chance it gets to survive and pass on its genes to the next generation. In order to gain a larger size, it needed to eat more and be able to reach more food. Of course, its small nose wasn't capable of doing that at the time. So, through natural selection, eventually the elephants that were bigger, had longer trunks, and therefore ate more, were more likely to pass on their genes to the next generation than their smaller counterparts, and therefore with each generation elephants got longer trunks.