During binary fission of a bacterium, which event occurs to produce two genetically identical daughter cells?

• A. Four haploid cells are produced after two rounds of nuclear division.
• B. The chromosome is replicated and the copies segregate as the cell elongates, followed by septum formation and cell division.
• C. Genetic material from two parent cells is exchanged, creating recombinant offspring.
• D. The nucleus undergoes mitosis, producing two nuclei before cytokinesis.

Answer: (B)

Verified step by step guidance

1. Understand that binary fission is the primary method of reproduction in bacteria, which are prokaryotic organisms lacking a nucleus.
2. Recognize that during binary fission, the bacterial chromosome, which is typically a single circular DNA molecule, is replicated to produce two identical copies.
3. After replication, the two copies of the chromosome segregate to opposite ends of the elongating cell, ensuring each future daughter cell will receive one copy.
4. Following chromosome segregation, the cell undergoes septum formation, where a division septum (a new cell wall) begins to form between the two chromosome copies.
5. Finally, the septum completes, and the cell divides into two genetically identical daughter cells, each containing one copy of the original chromosome.