wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

In the Meselson-Stahl experiment, if E.coli is allowed to replicate for three generations, the ratio between the number of DNA molecules with one strand labelled with N15 and the other strand with N14, to those with both strands labelled with N14 would be

A
1:1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
3:1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
1:3
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
2:3
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 1:3
Meselson and Stahl grew E.coli in a medium containing heavy nitrogen N15 for several generations. These cells ended up containing DNA having both the strands labelled with N15. These cells were then transferred to a medium containing lighter nitrogen (N14). At the end of 60 minutes, 3 rounds of replication would have been completed by one parental cell, and this would have resulted in 8 daughter cells. Of these, two cells would be “hybrid”, containing one strand labelled with N14 and the other with N15, while the remaining 6 molecules would possess DNA molecules having both strands labelled with N14. Thus, the ratio becomes 2:6, which when simplified, becomes 1:3.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
DNA Replication
BIOLOGY
Watch in App
Join BYJU'S Learning Program
CrossIcon