The restriction enzymes that cut the bacteriophage DNA cannot cut the bacterial chromosomal DNA. Explain this statement. A. The
bacteria can cut the viral DNA at its specific restriction site, but they cannot cut their own DNA since bacterial chromosomal DNA has altogether a different DNA sequence than the viral DNA. B. The bacteria can cut the viral DNA at its specific restriction site but protect their own chromosomal DNA by modifying its bases and blocking the restriction enzyme. C. The bacteria can cut the viral DNA at its specific restriction site but protect their own chromosomal DNA by modifying the restriction enzyme.
2 answers:
Answer:
B. The bacteria can cut the viral DNA at its specific restriction site but protect their own chromosomal DNA by modifying its bases and blocking the restriction enzyme.
Explanation:
There are two main reasons why bacteria cuts the viral DNA sequence but not its own.
1) There are specific restriction sites in the genome sequence of bacteriophage that restriction enzymes identify and target. These restriction sites are not present in the genome sequence of bacteria.
2) Even if sometimes the bacteria has a sequence resembling to bacteriophage and has the restriction site, still bacteria prevents the cleavage of its own chromosomes by methylating the bases of the restriction sites. When restriction site is methylated, bacteria just cannot chop it down that prevents it overall from degradation(please see the figure for better understanding).
Note: <em>Although option A can also somehow fit but option B is the perfect option because of the reason no 2.</em>
Hope it help!
You might be interested in