One turn of the helix in a B-form DNA is approximately of the length
| 1. | 0.34 nm | 2. | 3.4 nm |
| 3. | 2 nm | 4. | 20 nm |
Antiparallel strands of a DNA molecule means that
| 1. | the phosphate groups of two DNA strands, at their ends, share the same position |
| 2. | the phosphate groups at the start of two DNA strands are in opposite position (pole) |
| 3. | one strand turns clockwise |
| 4. | one strand turns anti-clockwise |
| 1. | T : 20%, G : 30% | 2. | T : 30%, G : 20% |
| 3. | T : 30%, G : 30% | 4. | T : 20%, G : 20% |