Watson
discovered the double helical structure of DNA while
looking at possible ways that two strands could fit
together. If the sugar-phosphate backbone were on the
outside of the molecule, the bases adenine, cytosine,
guanine and thymine would have to bond to each other
in some way.
Try
to get two of the bases to bond together. If you need
a hint, check back to the sections on
Hydrogen Bonding and Chargaff's
Rules.
Did
you find both pairs? If you've only found one, try and
find the other.
