Question

If the length of E.coli DNA is 1,360 micron and the distance between two base pairs is 0.34 nm. Then what will be the total number of base pairs in this DNA?

• A. $4\times {10}^6$
• B. $4\times {10}^7$
• C. $4\times {10}^8$
• D. $4\times {10}^9$

Answer 1

The correct option is A $4\times {10}^6$

The length of E.coli DNA is 1,360 micron = 1.36 mm $=1.36\times {10}^{-3}m$.
And distance between two base pairs = 0.34 nm $=0.34\times {10}^{-9}m$
So, the total number of base pairs $=1.36\times {10}^{-3}/0.34\times {10}^{-9}=4\times {10}^6$ base pairs.