Who is the unsung hero whose x-ray diffraction pictures of DNA actually helped in the discovery of DNA structure?

 Which shows the correct complementary base pairing for DNA?

The two strands of a DNA molecule are held together by hydrogen bonds between the:  _______

What does the theory of evolution emphasize?

How would increasing the temperature affect the reaction rate catalyzed by an enzyme?  

The differential distribution of tortoise shell (carapace), with a bent carapace on drier islands and straight on wetter islands, provides evidence that:

Carbon can form __________ covalent bond(s).

The section of DNA that is responsible for one particular inherited trait is called a 

Nitrogen can form __________ covalent bond(s).

Oxygen has 8 protons, 8 neutrons, and 8 electrons.  What is its atomic mass?