DNA Replication Models and Processes

Front

3 Models of DNA Replication

Back

Semi-Conservative, Conservative, Dispersive

Front

Model where the two strands of DNA unwind from each other, both acting as a template for a new complementary strand.

Back

Semi-Conservative Model

Front

Model with one copy made of new DNA strands and one copy made of old DNA strands.

Back

Conservative Model

Front

Model with two DNA molecules that are mixtures of parental and daughter DNA.

Back

Dispersive Model

Front

What was the purpose of the Meselson and Stahl experiment?

Back

To determine the correct model of DNA replication.

Front

What organism was used in the Meselson and Stahl experiment?

Back

Escherichia coli (E. coli)

Front

What type of nitrogen was E. coli grown first for 14 generations to make the DNA heavier?

Back

N15-ammonium chloride

Front

What method was used in Meselson and Stahl's Experiment to separate the heavy DNA?

Back

Density-gradient Centrifugation

Front

What type of nitrogen was E. coli grown in after N15 to make the new DNA strands from replication lighter?

Back

N14

Front

What did the first cell division in the Meselson and Stahl experiment show?

Back

The DNA was half as heavy, indicating a mixture of heavy and light nitrogen.