Which Of The Following Is An Example Of An Epigenetic Change?

Epigenetics: Definition & Examples

Epigenetics literally means "higher up" or "on tiptop of" genetics. It refers to external modifications to DNA that turn genes "on" or "off." These modifications do non change the Dna sequence, but instead, they impact how cells "read" genes.

Examples of epigenetics

Epigenetic changes alter the physical structure of Dna. One example of an epigenetic change is DNA methylation — the improver of a methyl group, or a "chemical cap," to part of the Deoxyribonucleic acid molecule, which prevents certain genes from beingness expressed.

Some other example is histone modification. Histones are proteins that DNA wraps around. (Without histones, DNA would be too long to fit inside cells.) If histones squeeze Deoxyribonucleic acid tightly, the DNA cannot be "read" by the cell. Modifications that relax the histones can make the Deoxyribonucleic acid accessible to proteins that "read" genes.

Epigenetics is the reason why a peel prison cell looks different from a brain cell or a muscle cell. All three cells contain the aforementioned DNA, but their genes are expressed differently (turned "on" or "off"), which creates the dissimilar cell types.

Epigenetic inheritance

Information technology may be possible to pass down epigenetic changes to future generations if the changes occur in sperm or egg cells. Most epigenetic changes that occur in sperm and egg cells get erased when the two combine to grade a fertilized egg, in a procedure chosen "reprogramming." This reprogramming allows the cells of the fetus to "start from scratch" and make their own epigenetic changes. But scientists retrieve some of the epigenetic changes in parents' sperm and egg cells may avoid the reprogramming process, and brand it through to the next generation. If this is truthful, things like the food a person eats before they conceive could affect their future child. However, this has not been proven in people.

Epigenetics and cancer

Scientists at present think epigenetics can play a part in the development of some cancers. For example, an epigenetic change that silences a tumor suppressor cistron — such as a factor that keeps the growth of the cell in check — could pb to uncontrolled cellular growth. Another example might be an epigenetic alter that "turns off" genes that aid repair damaged Deoxyribonucleic acid, leading to an increase in DNA impairment, which in turn, increases cancer risk.

Rachael has been with Live Science since 2022. She has a master'southward caste in journalism from New York University's Scientific discipline, Health and Environmental Reporting Plan. She too holds a B.S. in molecular biology and an M.South. in biological science from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Mail service and Scientific American.