A ds DNA is 100 kbp long. The number of nucleotides, number of complete turns in the molecule and the length of the DNA molecule will be:-

Options

A. `1.2xx10^(5),20000,3.4xx10^(4)nm`
B. `2xx10^(5),10000,3.4xx10^(4)nm`
C. `2xx10^(5),10000,0.34xx10^(4)nm`
D. `2xx10^(5),100000,3.4xx10^(4)nm`

Answer

B

Explanation

(i) 100 kbp=100000 bp or 200000 bases
(ii) 10 bp forms 1 turn of DNA & therefore, 100000 bp form 10000 turns.
(iii) 10 bp are equal to 34Å and therefore, 100000 bp are equal to `3.4xx10^(4)nm` (or `3.4xx10^(5)`Å or `3.4xx10^(-5)m`)