Answer: uracil.
- A uracil
- B adenine
- C guanine
- D cytosine
Correct answer: A. uracil
Explanation: RNA uses uracil in place of thymine.
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.