Why was it necessary to add alcohol (isopropanol) to precipitate DNA? This is because:

Question

Why was it necessary to add alcohol (isopropanol) to precipitate DNA? This is because:

a.
The alcohol sterilizes the DNA.

b.
The alcohol dissolves the cell membranes.

c.
DNA is insoluble in water.

d.
DNA is insoluble in alcohol.

Answer 1

d. DNA is insoluble in alcohol.

Adding alcohol (isopropanol) to a DNA solution helps to precipitate or separate the DNA from other cellular components. DNA is not soluble in alcohol, so when alcohol is added, it causes the DNA to separate and form visible strands or clumps, which can then be collected and isolated.

Answer 2

The correct answer is d. DNA is insoluble in alcohol. When alcohol, such as isopropanol, is added to a DNA solution, it causes the DNA molecules to come out of solution and precipitate. This is because DNA has a higher affinity for water molecules than for alcohol molecules. As a result, the DNA molecules cluster together and become visible as a precipitate, making it easier to isolate and collect the DNA sample.