If E.coli was allowed to grow for 80 minutes (Meselson and Stahl experiment) then what would be the proportions of light and hybrid densities DNA molecules ?

	Light	Hybrid
1)	14	2
2)	6	2
3)	30	2
4)	62	2

Generation time for E.coli cells is 20minutes.

Therefore, No. of generation is 80minutes=80/20=4.

Meselson and Stahl started with Heavy DNA and grew the E.coli cells in a ¹⁴NH₄Cl.

Therefore after 4 generations, 14 were light and 2 were hybrid DNAs.