DNA and genomes

1. Deoxyribonucleic Acid (DNA)

Figure 2 : Pyrimidines have 1 nitrogenous cycle

Figure 3: Purines have 2 nitrogenous cycles

1.1 Nucleotides (continued)

There are 2 kinds of Nitrogenous bases:

• Pyrimidines (figure 2) - Cytosine and thymine each with 1 nitrogenous ring

• Purines (figure 3) - Adenine and guanine each with 2 nitrogenous rings