| I | II | |
| 1. | 2’ deoxyribose | Ribose |
| 2. | Ribose | 2’ deoxyribose |
| 3. | Adenosine | Adenylic acid |
| 4. | α glucose | β glucose |
| 1. | identical |
| 2. | coiled around each other |
| 3. | parallel to each other |
| 4. | complementary to each other |
At each step of ascent, the helical strand of DNA turns
| 1. | 36 degree | 2. | 34 degree |
| 3. | 20 degree | 4. | 180 degree |