THE MOLECULAR BASIS OF INHERITANCE
RECOMBINANT DNA
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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By cutting the covalent bonds in the nitrogenous base.
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By cutting the hydrogen bonds between the DNA strands.
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By cutting the phosphodiester bond between the deoxyribose sugar and the phosphate group.
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By cutting the glycosidic bonds between the deoxyribose sugar and the phosphate group.
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Detailed explanation-1: -Restriction enzymes cut DNA bonds between 3′ OH of one nucleotide and 5′ phosphate of the next one at the specific restriction site. Adding methyl groups to certain bases at the recognition sites on the bacterial DNA blocks the restriction enzyme to bind and protects the bacterial DNA from being cut by themselves.
Detailed explanation-2: -How do restriction enzymes work? Like all enzymes, a restriction enzyme works by shape-to-shape matching. When it comes into contact with a DNA sequence with a shape that matches a part of the enzyme, called the recognition site, it wraps around the DNA and causes a break in both strands of the DNA molecule.
Detailed explanation-3: -When restriction enzyme recognizes a DNA sequence, it hydrolyzes the bond between adjacent nucleotide & cuts through the DNA molecule. Restriction enzymes break phosphodiester bonds between the phosphate and the pentose sugar in sugar-phosphate backbone at the specific site.
Detailed explanation-4: -DNA nucleases catalyze the cleavage of phosphodiester bonds between deoxyribose and the phosphate residue within the backbone of DNA strands.