Answer: Fewer than 30,000 to 25,000 genes.
- A Fewer than 30,000 to 25,000 genes
- B About 100,000 genes
- C About 250,000 genes
- D Exactly 46 genes, one per chromosome
Correct answer: A. Fewer than 30,000 to 25,000 genes
Explanation: Contrary to earlier predictions, the HGP found the human genome contains only about 30,000 to 25,000 protein-coding genes or fewer.
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.