Biotechnology- Principles and Processes Question 7

7. Given below are four statements pertaining to separation of DNA fragments using Gel electrophoresis. Identify the incorrect statements.

[2019, Odisa]

(i) DNA is negatively charged molecule and so it is loaded on gel towards the Anode terminal. (ii) DNA fragments travel along the surface of the gel whose concentration does not affect movement of DNA. (iii) Smaller the size of DNA fragment, larger is the distance it travels through it. (iv) Pure DNA can be visualised directly by exposing to UV radiation.

(a) (i), (ii) and (iv)

(b) (i), (iii) and (iv)

(c) (i), (ii) and (iii)

(d) (ii), (iii) and (iv)

Show Answer

Answer : a

Hints & Solutions

(a)

  • DNA fragments are negatively charged molecules. They are separated by forcing them to move towards positive electrode i.e. anode. Increasing the concentration of a gel reduces the migration speed of DNA. DNA fragment can not be visualised directly but can be visualised under UV light after staining with ethidium bromide.