Answer:
Epigenetic phenomena
Explanation:
Epigenetics involves the changes in gene expression which is not as a result of changes in an individual's DNA sequence. In other words, it is a change in an individual's phenotype, without an alteration in the genotype.
It is involved in the normal functioning of cellular processes.
Examples of epigenetics is DNA methylation ( adding of a methyl group to a section of the DNA molecule) and histone modification such as histone acetylation (adding an acetyl group to the histone).
Epigenetic changes can switch off genes, hence, prevent the expression of those genes; it can also turn on genes, hence increase the expression of those genes.
Epigenetic changes can also results to diseases such as cancer.
Answer:
Option (C).
Explanation:
The plasma membrane of the eukaryotes are made of the phospholipid bilayer and the proteins are embedded or span the membrane bilayer. The carbohydrates are attached in moieties with the protein and lipid.
The fluidity of the membrane depends on the saturation, cholestrol and the hydrocarbon chains. The hydrocarbon chain is non polar in nature that allows the diffusion of non polar solutes across the membrane. This decreases the permeability of the polar molecules and the hydrophobic interactions in the membrane.
Thus, the correct answer is option (C).
<span>Hypertension is another term for high blood pressure. This occurs when there is too much pressure put on the blood vessels. The heart gets affected because it is pumping against the pressure, which causes strain on the heart. This can cause thickening of the heart walls, which can lead to other heart problems.
Stroke occurs when there blood supply to the brain is reduced or obstructed. This deprives the brain of oxygen and other nutrients. The occurrence of stroke increases with blood pressure because there is persistent pressure on the vessels which can ultimately lead to stroke. </span>
There are many different factors, but some are: the amount of natural resources (food, water, etc.), amount of predator/prey, and availability of shelter.
