What will be the length of a DNA molecule containing 10 million bp?
A. 340 mm
B. 34 mm
C. 3.4 mm
D. 0.34 mm

Calculating the Length of DNA with 10 Million Base Pairs

Introduction

DNA might be microscopic, but when you start counting base pairs, its length can be quite surprising! Here’s a classic biology question:

What will be the length of a DNA molecule containing 10 million base pairs?

Let’s break down the problem and calculate the exact length step by step.

Understanding the Basics

In the structure of B-form DNA:

• The distance between two consecutive base pairs is 0.34 nanometers (nm)
• This equals 0.34 × 10⁻⁶ millimeters (mm) per base pair

Step-by-Step Calculation

1 base pair (bp) = 0.34 nanometers = 0.00000034 mm
So, for 10 million bp (10,000,000 bp):

Length=10,000,000×0.00000034 mm=3.4 mm

Final Answer:

✅ Correct Option: C. 3.4 mm

Why This Matters

Knowing how to calculate DNA length is crucial in genetics, molecular biology, and biotechnology. It helps in:

• Estimating DNA size for gel electrophoresis
• Designing storage solutions for DNA
• Understanding genome organization in organisms

Conclusion

A DNA molecule with 10 million base pairs has a length of 3.4 mm. While that might not seem very long, remember this is just one molecule! DNA’s compact packaging in cells is a marvel of biological engineering.

Always remember: Multiply the number of base pairs by 0.34 nanometers to find the DNA length!