Norepinephrine, serotonin, and dopamine are all examples of . bodily humors. b. synaptic clefts.

The question is incomplete as it does not have the options which are:

A.bodily humors. B.synaptic clefts. C.neurotransmitters. D.growth hormones.

The correct answer will be option- C

Explanation:

Neurotransmitters are the chemicals released from the neurons at the synaptic junctions which helps in the transmission of the electrical impulse from one neuron to another.

The dopamine, serotonin and nor-epinephrine are the biogenic forms of neurotransmitters which are synthesized from the precursors of the amino acids. These neurotransmitters are produced in producing different functions in the body.

Thus, option- C is the correct answer.

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation:

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."