NEETZoologyMolecular Basis of Inheritance
What is the length of a DNA double helix in a typical mammalian cell?
Options
- AApproximately 10⁻⁶ m
- BApproximately 0.34 nm
- CApproximately 2.2 meters
- DApproximately 6.6 × 10⁹ bp
Correct answer
C. Approximately 2.2 meters
Step-by-step solution
Taken the distance between two consecutive base pairs as 0.34 nm (0.34×10–9 m), if the length of DNA double helix in a typical mammalian cell is calculated (simply by multiplying the total number of bp with distance between two consecutive bp, that is, 6.6 × 10⁹ bp × 0.34 × 10-9m/bp), it comes out to be approximately 2.2 meters . A length that is far greater than the dimension of a typical nucleus (approximately 10–6 m). How is such a long polymer packaged in a cell? If the length of E. coli DNA is 1.36 mm, can you