3) what structural problem prevents adenine from pairing with guanine? (1 point)
the bases are both short.
they lack phosphate groups.
they lack the deoxyribose group.
the bases are both long.

4. rosalind franklin contributed to the understanding of dna by (1 point)

producing images of dna molecules using x-rays.
figuring out that dna strands form a double helix.
conducting experiments that showed which nucleotides are