During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out
Answer: (B) DNA. Answer: (B) DNA Solution: During DNA isolation, RNA is removed by ribonuclease, proteins (histones) by protease, and other macromolecules by appropriate treatments; the purified DNA finally precipitates out on adding chilled ethanol, seen as fine threads.
- A.RNA
- B.DNA✓
- C.Histones
- D.Polysaccharides
Correct Answer
(B) DNA
Solution & Explanation
Answer: (B) DNA Solution: During DNA isolation, RNA is removed by ribonuclease, proteins (histones) by protease, and other macromolecules by appropriate treatments; the purified DNA finally precipitates out on adding chilled ethanol, seen as fine threads. Thus chilled ethanol precipitates DNA, not RNA/histones/polysaccharides which have already been removed. This is a direct NCERT statement. NCERT Reference: Ch 9, p.171, line(s) 40-41 — "treatment with protease. Other molecules can be removed by appropriate"