Question

If the length of E. coli DNA is 1.36 mm, then what will be the number of base pairs if distance between two consecutive base pairs is 0.34 nm?

• A. $6.6\times {10}^9$bp
• B. $3.3\times {10}^9$bp
• C. $4.0\times {10}^6$bp
• D. $2.3\times {10}^6$bp

Answer 1

The correct option is C $4.0\times {10}^6$bp

Length of DNA = No. of base pairs × distance between two base pairs.
1.36 mm $=x\times 0.34$nm
$\frac{1.36\times {10}^{6}nm}{0.34nm}=x$
$4.0\times {10}^{6}bp=x$