30. Dr. Doom has a DNA sequence of 2000 bp.Enzyme X and Enzyme Y restriction sites and their positions are indicated here. Recall that Enzyme X is methylation-sensitive, while Enzyme Y is not. Dr. Doom has a DNA sequence of 2000 bp.Enzyme X and Enzyme Y restriction sites and their positions are indicated here. Recall thatEnzyme X is methylation sensitive, while Enzyme Y is not.200O 10018002000 bp10001500Enzyme YEnzyme YEnzyme XEnzyme YEnzyme XIf this gene is methylated, which of the following combinations of DNA fragments wouldyou expect from this restriction digest?3 bands = 20o0 bp, 500 bp, and 1300 bpNo bands = DNA will be completely digestedO NoO4 bands 100 bp. 200 bp, 800 bp, and 900 bp5 bands 100 bp. 200 bp. 1000 bp. 1500 bp, and 1800 bp

Restriction enzymes are the enzymes which cut DNA at particular site.The correct answer is 4bands- 100bp, 200bp, 800bp, 900bp. Reason- As mentoned in question, enzyme X is methylation sensitive, hence, it wil not be able to cleave at its restriction sites during DNA or gene is methylated. Hnece, only restriction enzyme Y will carry out the function. Restriction enzyme Y has sites at 100bp, 1000bp and 1800bp on DNA. So, it will cut at 100bp mark first, yielding a 100bp DNA fragment. Then, it will cut at 1000bp mark (considered from 0bp point), hence, it will yield a fragment of (1000-100)bp = 900bp. Next, it will cut at 1800bp fragment and yield a fragment of (1800-1000)bp = 800bp. At, last remaining fragment from 1800bp to 2000bp = (2000-1800)bp = 200bp3 bands is not the correct option as 4 bands are yielded when enzyme Y cuts at its restriction sites. No bands is not correct option since enzyme Y has its restriction site at which it will cleave DNA. 5 bands is not correct option since no 1500bp and 1800bp fragments are yielded during cleaving or cutting by enzyme Y.