Which of the following is a substance that acts at a long distance from the site at which it is secreted? view available hint(s)

a. hormone local regulator synaptic signal
b. neurotransmitter paracrine signal

The correct answer is A hormone local regulator synaptic signal.

Explanation:

Hormones are called chemical messengers because they carry chemical and biochemical information from one cell to another cell by a process called signal transduction.

      The hormonal signal transduction is generally mediated by endocrine signaling in which hormone is secreted from one gland and then is transported via the blood stream to binds to the receptor present in the target cell.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.