Question

imagine a cell in human body. this differentiated cell has shut off many genes. describe 3 ways that genes are shut off in this cell

Answer 1

Gene regulation in cells occurs during transcription, translation and in DNA level also.

# Epigenetic modifications are occuring at DNA level. They are

DNA methylation

Methylation of DNA at the cytosine and adenine bases repress the gene expression. Methylation causes the DNA to be not accessible for transcription enhancer proteins to bind . So transcription will be supressed.

Histone deacetylation

Deacetylation of histone molecules leads to the gaining of positive charge in the histone proteins. So this cause the histone proteins to tightly bind with the DNA thereby, DNA will bot be accessible for the RNA polymerase and transcription factor to bind for the expression of the gene.

# Gene silencing at RNA level

RNA silencing; miRNA degrades the targetive transcript and silence the gene expression.