Read the following passage and answer the questions that follow:-
Deeksha lives in a society where a robbery occurred last night. Robbers came into the flat and murdered the old lady residing there. Police came and restricted the entry into the flat. They took samples from the room, where the dead body was found. While examining, they found that there is some blood and tissue in the nails of an old lady. According to their observation, police filtered out their inspection to three suspects viz. servant, cook, and milkman. Finally, after two days of robbery, police caught the criminal. It was the old lady’s cook. Deeksha was amazed to see how quickly the police completed and shut the case. She asked the inspector how they did it? The policeman told her that it become possible due to the sample collected from the victim, which lead them to the criminal. The sample taken from nail scraping was amplified using PCR and then tested.

Which of the following statement is correct?

The RNA can be removed by treatment with ribonuclease whereas proteins can be removed by treatment with protease.

The correct answer is Option (3) -DNA purified from the cell is precipitated by adding chilled ethanol.

The incorrect Statements can be corrected as :

Taq polymerase, which is isolated from bacterium Thermus aquaticus is stable at high temperatures also(95^oC).
With the help of DNA ligase, the complementary sticky ends of the DNA are joined to produce rDNA.

The correct statement is :

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.