- A Largely light (14N-14N)
- B Largely heavy (15N-15N)
- C Hybrid density (15N-14N)
- D A mixture of light and heavy, with little hybrid
Correct answer: C. Hybrid density (15N-14N)
Explanation: After one generation, all DNA molecules showed an intermediate (hybrid) density, consistent with each molecule having one heavy (15N) parental strand and one light (14N) new strand, confirming semiconservative replication.
Concept context
DNA structure, replication, transcription, translation, the genetic code, and gene regulation (lac operon). The single most important chapter for NEET molecular biology.