Concerning the nitrogen-containing bases that participate in nucleotides, what is the difference among DNA and RNA?
In DNA nucleotides can be formed of adenine (A), thymine (T), cytosine (C) or guanine (G). In RNA nucleotides can also have adenine (A), cytosine (C) or guanine (G), though, instead of thymine (T) there is uracil (U).
According to the Watson-Crick model how many polynucleotide chains does a DNA molecule have?
The DNA molecule is produced by two polynucleotide chains bound in antiparallel mode (5'-3' to 3'-5') and forming a helical structure.
Nucleic Acid Review - Image Diversity: DNA double helix