Question

Which of the following are typically used to determine differences in DNA sequence between individuals? Select all that apply.

a) cloning

b) DNA fingerprinting of STRs

c) DNA sequencing

d) RFLP analysis

e) gel-filtration chromatograpgy

f) western blot

Answer 1

Techniques used to determine differences in DNA sequence between individuals are DNA sequencing and RFLP analysis..The options are c and d.

DNA sequencing is the technique of identifying the sequence of nucleotides in a piece of DNA.There are two DNA sequencing technique.Sanger DNA sequencing and Nextgen DNA sequencing.DNA sequencing has may applications in biotechnology,forensic biology,medical diagnosis etc.By sequencing the DNA ,mutated genes can be identified and can diagnose different diseases like various cancers.By this technique,difference in DNA sequence between individuals can be identified.

RFLP analysis stands for Restriction fragment length polymorphism analysis.It is the method of arranging DNA on the basis of size of fragments that is formed when DNA is digested with a restriction enzyme.Restriction enzymes cut DNA fragments at different length.RFLP analysis can be used to determine difference in DNA sequence between individuals.Because if two individuals have difference in their DNA sequence at a restriction site,the restriction enzyme cut the DNA at different lengths.

Other techniques like cloning,DNA finger printing,gel filtration chromatography and western blot cannot sequence the DNA.Cloning is process of producing individuals with identical DNA.DNA fingerprinting is the process of comparing the DNA of two individuals.This is used to identify victims in a crime scene,solve paternity dispute,study biodiversity of species etc.This technique cannot sequence the DNA.Gel filtration chromatography is used to separate molecules according to their size and molecular weight.It is applicable to large molecules like protein,polymers etc.Western blot is a technique used to separate and identify proteins.It doesn't sequence DNA.