Answer: Three.
- A One
- B Two
- C Three
- D Four
Correct answer: C. Three
Explanation: Guanine pairs with cytosine through three hydrogen bonds, making G-C pairs more stable than the two-bonded A-T pairs.
Helicase unwinds the double helix at the replication fork; one new strand (leading) is synthesised continuously toward the fork, while the other (lagging) must be made in short, separate Okazaki fragments because DNA polymerase only adds nucleotides 5'→3'.
Concept context
DNA structure, replication, transcription, translation, the genetic code, and gene regulation (lac operon). The single most important chapter for NEET molecular biology.