WorksheetsMeselson and Stahl IB Bio
Total questions: 11
Worksheet time: 9mins
The Meselson-Stahl experiment demonstrated that DNA replication produces two DNA molecules each composed of
Two old strands
Two new strands
One old strand and one new strand
two strands with variable proportions of new and old DNA.
Starting with 15N15N (heavy) DNA, and after TWO generations in the 14N medium, Escherichia coli cells will contain
25% 15N15N DNA, 50% 15N14N DNA, and 25% 14N14N DNA.
50% 15N15N DNA and 50% 14N14N DNA.
50% 15N15N DNA and 50% 15N14N DNA.
50% 15N14N DNA and 50% 14N14N DNA.
25% 15N14N DNA and 75% 14N14N DNA.
Starting with 15N15N (heavy) DNA, and after THREE generations in the 14N medium, E. coli cells will produce the following band(s) in density-gradient centrifugation:
a single band of DNA with medium density.
one band of light DNA and one band of DNA with medium density.
one band of heavy DNA and one band of DNA with medium density.
one band of heavy DNA and one band of light DNA.
three bands corresponding to DNA of light, medium and heavy density.
Which model does NOT predict that after one replication both DNA molecules will be a 50/50 mix of original and new DNA?
conservative
semi-conservative
dispersive
In the Meselson-Stahl experiment, E.coli was transfered from 15N medium to 14N medium. Centrifugation of DNA after 20 minutes in 14N produced ____ and disproved the ____ model.
1 intermediate band, conservative
1 intermediate band, dispersive
1 heavy band and 1 light band, semi-conservative
1 light and 1 intermediate band, dispersive
In the Meselson-Stahl experiment, E.coli was transfered into 14N medium from 15N medium. The bacteria is incubated and reproduced up to 2 generation of offsprings. Centrifugation of DNA after 40 minutes in 14N produced ____ and disproved the ____ model.
1 light and 1 intermediate band, dispersive
1 light and 1 intermediate band, conservative
1 intermediate band, dispersive
1 heavy and 1 light band, semi-conservative
What is the end result of DNA replication?
2 semi-conservative strands of DNA
1 semi-conservative strand of DNA
Half of a semi-conservative strand.
Nothing is created
This is the correct model for DNA Replication.
True
False
This is the correct model for DNA Replication.
True
False
This is the correct model for DNA Replication.
True
False
