Meselson and Weigle Grew One Strain of Bacteriophage Lambda with Alleles

Multiple Choice

Meselson and Weigle grew one strain of bacteriophage lambda with alleles A and B in heavy isotopes and another strain with alleles a and b in light isotopes.Both loci are located near the end of the viral chromosome.Which statement best describes their results and conclusions?

A) They visualized the broken chromosomes under a microscope and concluded that DNA was exchanged between light and heavy chromosomes during recombination.
B) They found a gradient of all densities of recombinant chromosomes and concluded that DNA was not exchanged between light and heavy chromosomes during recombination.
C) They found that some A b genetic recombinants were almost as dense as the A B parent chromosome and concluded that DNA was exchanged between light and heavy chromosomes during recombination.
D) They found that some A b genetic recombinants were almost as dense as the A B parent chromosome and concluded that DNA was not exchanged between light and heavy chromosomes during recombination.