Margaret wants to create a comparison for hormones to her understand their function better. which of the comparisons below is the best?

-a hormone is like an e-mail with instructions from someone’s boss.

-a hormone is like a key for a lock.

-a hormone is like a lock that needs a particular key.

-a hormone is like an employee who follows instructions from the boss.

-A hormone is like an employee who follows instructions from the boss.

Explanation:

Hormones are essential for the functioning of the human body and act by regulating the function of other cells. Unlike other substances, such as neurotransmitters, they are able to maintain their action for a longer time. They are like an employee who follows the boss's instructions.

Despite being released into the blood and reaching a large amount of cells, they act only on the target cell. This means that a given cell will only be stimulated or inhibited by the action of a specific hormone.

In the membrane of each target cell there is a hormone receptor, a protein capable of binding to the hormone. Each receptor only combines with a certain hormone, ie it is a specific binding. Importantly, if a hormone is in large quantities in the bloodstream, the cell may decrease the number of receptors in its membrane. If decreased, it may increase its receptors. There are also hormones that communicate with receptors in the cytoplasm, such as steroid hormones.

b) the heart is a pump made of muscle and that is difficult to grow in the lab.