| I: | usually defined as number of nucleotides (or a pair of nucleotide referred to as base pairs) present in it. |
| II: | is the characteristic of an organism. |
| A: | Messenger |
| B: | Structural role |
| C: | Adaptor molecule |
| D: | Catalytic role |
| E: | Genetic material in some viruses |
| I: | Cytosine is common for both DNA and RNA. |
| II: | Adenine is present in DNA at the place of Thymine. |
| III: | Thymine is present in DNA. |
| IV: | Uracil is present in RNA at the place of Thymine. |