Question

The charge present on the DNA backbone is negative. The force required to accelerate the molecules towards anode is directly proportional to the number of ____________

(a) sugar molecules

(b) nitrogenous bases

(c) phosphate groups

(d) both phosphate group and sugar molecules

This question was addressed to me by my school principal while I was bunking the class.

My enquiry is from Gel electrophoresis, Oligonucleotide  & Microarrays topic in chapter Basics of Genetic Engineering of Genetic Engineering

Answer 1

Correct answer is (c) phosphate groups

To explain I would say: The DNA backbone is negatively charged because of the phosphate groups. Hence, the force required to move the molecules towards anode is directly proportional to the number of phosphate groups present.