Question

How does DNA methylation regulate gene activity?

a. by inhibiting RNA polymerase
b. by adding methyl groups to the cytosine of CG doublets in DNA
c. increasing the level of transcription by promoting the binding of transcription factors to DNA
d. by changing DNA-DNA hydrogen bonding

Answer 1

DNA methylation regulates gene activity by adding methyl groups to the cytosine of CG doublets in DNA. Methylation can lead to lowered levels of gene expression. The addition of methyl groups changes how the DNA interacts with proteins, affecting gene transcription.

Step-by-step explanation:

DNA methylation is a form of epigenetic regulation that influences gene activity by adding methyl groups to the cytosine of CG doublets in DNA.

Methylation commonly leads to lowered levels of gene expression. The addition of methyl groups to DNA can change how the DNA interacts with proteins, including the histone proteins that control access to genes. Highly methylated regions of DNA with deacetylated histones are tightly coiled and transcriptionally inactive.