How does a bacterial cell protect its own dna from restriction enzymes?

by adding methyl groups to adenines and cytosines is the correct answer.

Explanation:

Bacteria cell prevents its own DNA from the restriction enzymes by methylation of restriction sites.

Methylation of DNA is the common method to modify the function of DNA and bacterial DNA is very methylated.

Bacterial has restriction enzymes which is called as endonucleases and its function is to cleave the double-strand DNA into fragments at the specific sites.