E. coli chromosomes in which every nitrogen atom is labeled (that is, every nitrogen atom is the heavy isotope 15N instead of the normal isotope 14N) are allowed to replicate in an environment in which all the nitrogen is 14N. Using a solid line to represent a heavy polynucleotide chain and a dashed line for a light chain, sketch each of the following descriptions:a. The heavy parental chromosome and the products of the first replication after transfer to a 14N medium, assuming that the chromosome is one DNA double helix and that replication is semiconservative.b. Repeat part a, but now assume that replication is conservative.c. If the daughter chromosomes from the first division in 14N are spun in a cesium chloride density gradient and a single band is obtained, which of the possibilities in parts a and b can be ruled out? Reconsider the Meselson and Stahl experiment: What does it prove?
E. coli chromosomes in which every nitrogen atom is labeled (that is, every nitrogen atom is the heavy isotope
15N instead of the normal isotope 14N) are allowed to replicate in an environment in which all the nitrogen is 14N.
Using a solid line to represent a heavy polynucleotide
chain and a dashed line for a light chain, sketch each of
the following descriptions:
a. The heavy parental chromosome and the products
of the first replication after transfer to a 14N medium,
assuming that the chromosome is one DNA double
helix and that replication is semiconservative.
b. Repeat part a, but now assume that replication is
conservative.
c. If the daughter chromosomes from the first division
in 14N are spun in a cesium chloride density gradient
and a single band is obtained, which of the possibilities
in parts a and b can be ruled out? Reconsider the
Meselson and Stahl experiment: What does it prove?
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 2 images
