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Restriction enzymes, often called 'molecular scissors', act on DNA by:
AJoining broken DNA fragments together
BCutting DNA at specific base-pair sites
CCopying DNA into many new strands
DSynthesising RNA from a DNA template
Answer & Solution
Correct answer: B. Cutting DNA at specific base-pair sites
1. Restriction enzymes recognise a specific palindromic sequence called the restriction site.
2. They cleave the phosphodiester bond there, cutting DNA at specific positions, earning the name molecular scissors.
3. Joining fragments is done by DNA ligases, so option A is a deliberate trap.
4. Hence the answer is B.
_Source: Samacheer Kalvi (TN SCERT) Class 10 Science, Unit "Breeding and Biotechnology", p.299_
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