Answer:
The correct answer will be option-D
Explanation:
Stem cells are the cells which have the ability to form different types of cells. They differentiate and specializes to perform different functions in the body and thus forms the different cells.
The differentiation and specialization are controlled at the gene level by different patterns of gene expression. The pattern of gene expression is not fully understood during development but research have shown that the gene expression is influenced by the different environmental signals and internal regulators.
Thus, option-D is the correct answer.
The answer is because it lowers the number of chromosomes in half, ensuring that the fusion will have the appropriate amount of chromosomes after the fusing of the sperm and the egg.
In humans, new neurons are continually born
throughout adulthood in two regions of the brain:
<span>·
</span><span>The subgranular
zone (SGZ), part of the dentate gyrus of
the hippocampus.</span>
<span>·
</span><span>The striatum;
however the adult-born neurons are a type of interneuron,
not a type that projects to other brain areas.</span>[5]
<span>In other species of mammals, particularly rodents,
adult-born neurons also appear in the olfactory
bulb. In humans, however, few if any olfactory bulb neurons are
generated after birth.</span>
<span> </span>
