In 1953, the scientists James Watson and Francis Crick published their landmark findings on the structure of DNA. Watson and
Crick deduced the structure of DNA by unifying evidence that they collected from several scientists who were also socking to
answer this important question.
Identify the pieces of evidence describing the features of DNA that Watson and Crick used to determine the structure
of DNA.
$\boxed{ }$ The diameter of the DNA double helix is 2 nanometers, with each purine-pyrimidine base pair spanning an
equivalent distance between the two chains,
$\boxed{ }$ The nitrogenous bases on each DNA helix are arranged perpendicularly to the central axis.
$\boxed{ }$ A purine base forms covalent bonds with a pyrimidine base located on the opposite DNA helix.
$\boxed{ }$ A purine base forms hydrogen bonds to pair with a pyrimidine base located on the opposite DNA strand.
Specifically, A pairs with T, and C pairs with G.
$\boxed{ }$ The sugar-phosphate backbones of each DNA helix run antiparallel to one another.
$\boxed{ }$ The two chains are parallel, both running in a 5' to y direction.
