Question

If the length of E. coli DNA is 1.36 mm, can you calculate the number of base pairs in E.coli?

Answer 1

Step 1: Equation
Total length of double helical DNA structure = total number of base pairs ✖ distance between the consecutive base pairs Therefore, total number of base pairs = total length of double helical DNA structure/distance between the consecutive base pairs
Step 2: Calculation
Given

• Length (total) of double helical DNA structure of E.coli=1.36 mm
• Note: 1.36mm =1.36 ✖ 10−3 m
• Distance between the consecutive base pairs = 0.34 ✖ 10−3m

In the above equation, let total base pairs (asked in question) be = ‘a’. Then substituting the given values in equation we get:-
1.36mm = a ✖ 0.34 ✖ 10−9m
a = 1.36 ✖10−3m / 0.34 ✖ 10−9m
a = 4 ✖ 106 bp
Final answer
4 ✖ 106bp