Before a eukaryotic cell divides, what must be duplicated during S phase to ensure each daughter cell receives a complete set of genetic information?

• A. The mRNA transcripts for all genes
• B. The phospholipid bilayer of the plasma membrane
• C. The cell’s DNA (chromosomes)
• D. The ribosomes and the nucleolus

Answer: (C)

Verified step by step guidance

1. Understand the role of the S phase in the cell cycle: S phase (Synthesis phase) is the part of interphase where the cell duplicates its genetic material to prepare for cell division.
2. Identify what genetic information consists of in a eukaryotic cell: The genetic information is stored in the DNA molecules organized into chromosomes within the nucleus.
3. Recognize that for each daughter cell to receive a complete set of genetic information, the DNA must be precisely duplicated during S phase.
4. Note that other cellular components like mRNA transcripts, the plasma membrane, ribosomes, and the nucleolus are not duplicated during S phase; their replication or synthesis occurs at different times or by different mechanisms.
5. Conclude that the key event during S phase is the replication of the cell's DNA (chromosomes), ensuring each daughter cell inherits an identical genome.