Identify the key structural features of a DNA molecule. Mark all that apply:
A. DNA strands are antiparallel and include a 5' end and a 3' end.
B. Strong ionic bonds and hydrophobic interaction hold DNA together.
C. DNA contains the nucleotide bases adenine, thymine, guanine, cytosine, and uracil.
D. DNA is most often found as a left-handed helix, commonly referred to as Z-DNA.
E. The backbone of DNA is made of a sugar and a phosphate molecule.
F. DNA bases are always paired purine with pyrimidine.