Fragments of DNA formed after treatment with endonucleases are separated by the technique of _______a) polymerase chain reactionb) gene amplificationc) blottingd) gel electrophoresis

The fragments of DNA formed after treatment with endonucleases are separated by the technique of d) gel electrophoresis.

Here's a step-by-step explanation:

1. Endonucleases are enzymes that cleave the phosphodiester bond within a polynucleotide chain. They are used to cut DNA into smaller fragments.

2. These smaller fragments of DNA, however, are mixed together and need to be separated.

3. This is where gel electrophoresis comes in. Gel electrophoresis is a technique used to separate DNA fragments (or other macromolecules, like RNA and proteins) according to their size.

4. The DNA fragments are loaded into a gel, and an electric current is applied. DNA is negatively charged, so when an electric current is applied, the DNA fragments will move towards the positive electrode.

5. Smaller fragments move through the gel more quickly than larger ones, so the fragments end up separated by size.

6. The separated DNA fragments can then be visualized under UV light after staining with a dye like ethidium bromide, which intercalates between the bases of DNA and fluoresces under UV light.

So, the correct answer is d) gel electrophoresis.