Question

A prokaryotic organism has DNA of length 2250 microns. Considering the distance between adjacent base pairs as 0.34 nm. How many base pairs are present in prokaryotic DNA?

• A. 4.6 X 10${}^6$
• B. 4.6 X 10${}^9$
• C. 6.6 X 10${}^6$
• D. 6.6 X 10${}^9$

Answer 1

The correct option is C 6.6 X 10${}^6$

DNA stands for deoxyribonucleic acid. It is a polymer of nucleotides. Each nucleotide consists of :
I. Deoxyribose sugar
II. Nitrogenous base
III. Phosphate group

Length of prokaryotic DNA = 2250 microns = 2250 x 10${}^{-6}$ m
Further, the distance between adjacent pairs= 0.34 nm= 0.34 x 10${}^{-9}$ m
The number of base pairs = total length of DNA / distance between adjacent base pairs
= 2250 x 10${}^{-6}$/ 0.34 x 10${}^{-9}$
= 6.6 x 10${}^6$

Hence the correct answer is option C.