In: Biology
In the Meselson - Stahl experiment, if after the first round of replication, the DNA had been denatured at high temperature before its centrifugation in a column of cesium chloride, which two models would have shown the same sedimentation pattern?
Group of answer choices
semiconservative and dispersive
conservative and dispersive
all three would have shown the same sedimentation pattern
semiconservative and conservative
none of the three would have had the same sedimentation pattern
Ans:
Semiconservative and dispersive
Explanation:
If after the first round of replication, the DNA had been denatured at high temperature before its centrifugation in a column of cesium chloride, Semiconservative and dispersive models would have shown the same sedimentation pattern because both the models produce hybrid DNA (15N- 14N) after 1st round of repliction. If the cells grown on heavy medium (15N), are transferred to light medium (14N). After one round of replication both the model are produce hybrid DNA (15N- 14N). In conservative replication, If the cells were initially grown on heavy medium (15N) and then transferred to light medium (14N). After one generation in conservative replication, they are produce Half heavy (15N) and half light DNA (14N) in CSCl equilibrium density gradient, no hybrid DNA are produce.