Which of the following best describes Rosalind Franklin's contribution to our understanding of the structure
of DNA? a. She created many models of DNA based on what was known about its properties, and
eventually figured out that the structure of DNA is a double helix,
b. She purified large amounts of DNA, stretched the fibers so the strands were parallel, and used an X-ray beam to produce an image of the molecule.
c. She isolated DNA from many different organisms, and discovered that in every sample,
the amount of guanine was almost exactly equal to the amount of cytosine.
d. She used radioactive phosphorus and sulfur to produce radioactive viruses, then allowed
these viruses to infect bacteria. She found that DNA was the transforming material.
Answer: b. She purified large amounts of DNA, stretched the fibers so the strands were parallel, and used an X-ray beam to produce an image of the molecule.