Question

In the Meselson and Stahl experiment, the starting Escherichia coli culture was grown in heavy (15N) medium; the DNA was 15N15N. After TWO generations of growth in light (14N) medium, the DNA of the E. coli cells contained A) 25% 15N15N DNA, 50% 15N14N DNA, and 25% 14N14N DNA. B) 25% 15N14N DNA and 75% 14N14N DNA. C) 50% 15N14N DNA and 50% 14N14N DNA. D) 50% 15N15N DNA and 50% 14N14N DNA. E) 50% 15N15N DNA and 50% 15N14N DNA.

Name: in the meselson and stahl experiment the starting escherichia coli culture was grown in heavy 15n medium the dna was 15n15n after two generations of growth in light 14n medium the dna of the 18723
Uploaded: 2023-06-13T10:12:27-08:00
Duration: 2 min 22 s
Channel: Adi S
Description: in the meselson and stahl experiment the starting escherichia coli culture was grown in heavy 15n medium the dna was 15n15n after two generations of growth in light 14n medium the dna of the 18723

          In the Meselson and Stahl experiment, the starting Escherichia coli culture was grown in heavy (15N) medium; the DNA was 15N15N. After TWO generations of growth in light (14N) medium, the DNA of the E. coli cells contained
A) 25% 15N15N DNA, 50% 15N14N DNA, and 25% 14N14N DNA.
B) 25% 15N14N DNA and 75% 14N14N DNA.
C) 50% 15N14N DNA and 50% 14N14N DNA.
D) 50% 15N15N DNA and 50% 14N14N DNA.
E) 50% 15N15N DNA and 50% 15N14N DNA.

Added by Lorenzo C.

Biology for AP Courses

Julianne Zedalis, John Eggebrecht

Instant Answer

Solved by Expert Adi S

06/13/2023

Step 1

In the first generation, the starting DNA is 15N15N. When the E. coli cells replicate in the presence of 14N, the new DNA strands will be made with 14N. So, after the first generation, we will have 50% 15N15N DNA and 50% 15N14N DNA. Show more…

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In the Meselson and Stahl experiment, the starting Escherichia coli culture was grown in heavy (15N) medium; the DNA was 15N15N. After TWO generations of growth in light (14N) medium, the DNA of the E. coli cells contained A) 25% 15N15N DNA, 50% 15N14N DNA, and 25% 14N14N DNA. B) 25% 15N14N DNA and 75% 14N14N DNA. C) 50% 15N14N DNA and 50% 14N14N DNA. D) 50% 15N15N DNA and 50% 14N14N DNA. E) 50% 15N15N DNA and 50% 15N14N DNA.