<u>N</u><u><em>atural selection acts on existing heritable variation</em></u>
Answer: Option C
<u>Explanation:</u>
Natural selection is a process that occurs in nature as a key to evolution. It also goes hand with the survival of the fittest. Nature always selects the best trait to survive or get accustomed to the surrounding by undergoing modifications.
It acts on the genotype of the existing generation and causes variation in the future generation. So the population over generations get to have acquired the variations in their body, structure so that it is adaptable to the surrounding.
Answer:
<h2>
certain genes being expressed in some cells and not in others</h2>
Explanation:
The DNA is present in every cell of the multicellular organism but that does not mean that every cell will perform the same function.
The function of the cell is decided during the cell differentiation phase the function of the cell is determined by the expression of specific genes. Expression of these genes controls the functions of the cell.
In the given question the differences in the structure and function of the brain and kidney arise due to different expression of genes in different cells.
Thus, the selected option is the correct answer.
Answer: Because they are what gives DNA, and keeps track of the heredity of the parent(s).
Explanation:
Nucleic Acid, DNA, (Deoxyribonucleic acid) is the blueprint of making genetic material.
I looked this question up for you and this is what I found I hope it's helpful for you
A. they arose out of Africa less than 200,00 years ago