Answer :
Final answer:
In gel electrophoresis, DNA fragments move towards the positive electrode due to their net negative charge from phosphate groups, hence correct answer is D) phosphate groups have a net negative charge.
Explanation:
This net negative charge allows the DNA to migrate from the negative to the positive end of the gel under an electric field. The separation of DNA fragments by size is facilitated by the gel matrix, through which smaller molecules move more rapidly than larger ones.
The correct answer to the provided question is D. phosphate groups have a net negative charge. This is why nucleic acids, including DNA, move toward the positive electrode in a gel electrophoresis setup.
Using a stain like ethidium bromide reveals the DNA fragments as distinct bands across the gel electrophoresis slab, allowing for visual analysis of DNA fragment sizes, which is crucial in various biological and medical research applications.
