question_answer

Directions : (26 - 30)

Read the passage given below and answer the following questions.

Nucleic acid is the genetic material of all organisms without exception. In majority of organisms this is deoxyribonucleic acid or DNA. In order to cut the DNA with restriction enzymes, it needs to be in pure form, free from other macro molecules. Since the DNA is enclosed within the membranes, we have to break the cell open to release DNA along with other macromolecules such as RNA, proteins, polysaccharides and also lipids. This can be achieved by treating the bacterial cells or plant or animal tissue with enzymes such as lysozyme (bacteria), cellulase (plant cells), chitinase (fungus) etc. As genes are located on long molecules of DNA interwined with proteins such as histones. The RNA can be removed by treatment with ribonuclease whereas proteins can be removed by treatment with protease. Other molecules can be removed by appropriate treatments and purified DNA ultimately precipitates out after the addition of chilled ethanol. This can be seen as collection of fine threads in the suspension.

Nucleic acid is fragmented by which of the following enzyme:

A) Ligases

B) Proteases

C) Nucleases

D) Polymerases