The nervous system communicates through electrical impulses and the communication is very fast. It works in a relay fashion, from point to point comparable to the way the old telephones systems used to work.
The endocrine system communicates by chemical signals via the bloodstream. Hormones are secreted into the blood and extra cellular fluids, then transported to target cells, which must bear a receptor to be able to bind to a specific hormone, and respond.
Hormones are chemical messengers secreted into blood or extracellular fluid that affect the function of other cells.
Endocrine communication is not quite as fast as the nervous system communication
The incorrect among the choices is "<span>direct signaling involves the activation of g proteins"
This is incorrect because direct signaling does not involve the activation of g proteins rather it involves the activation of ion channels resulting to either an excitation reaction (depolarization of the membrane) or an inhibition reaction (hyperpolarization of the membrane); and this will ultimately affect the action of the organ the nerve is innervating.</span>
Scientists most often produce new genetic variations of organisms by causing mutations with radiation or chemicals and then selectively breeding in order to emphasize the desired traits in the new variations. The Dachshund is an example of this. By breeding two dogs with a similar mutation that caused student legs and elongated backs breeders were able to create a new variation not found in nature.
Demonstrative pronoun is the answer.
