In 1952, Rosalind Franklin took an X-ray photograph that revealed the structure of DNA. James Watson and Francis Crick followed
up on this discovery in 1953. They discovered that the molecule has a specific shape that can best be described as — A. a single strand containing 4 different bases that vary depending on the type of DNA
B. ladder-shaped, containing 5 nitrogenous bases that bond to one another
C. triple-stranded, with bonds between each strand holding the three strands together
D. double-stranded and twisted, with bases bonded to other bases which hold the strands together
