Which of the following processes does NOT occur during binary fission in dividing bacteria?

• A. Septum formation
• B. Replication of the bacterial chromosome
• C. Formation of mitotic spindle
• D. Partitioning of cytoplasm

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the process of binary fission, which is the method by which bacteria reproduce asexually. It involves the replication of the bacterial chromosome, growth of the cell, and division into two daughter cells.
2. Step 2: Identify the key events in binary fission: (a) replication of the bacterial chromosome, (b) formation of a septum (a dividing wall) between the two new cells, and (c) partitioning of the cytoplasm to separate the two daughter cells.
3. Step 3: Recognize that the formation of a mitotic spindle is a process specific to eukaryotic cell division (mitosis), where spindle fibers help segregate chromosomes. Bacteria do not have mitotic spindles because they lack a nucleus and the complex mitotic machinery.
4. Step 4: Compare the options given: septum formation, replication of the bacterial chromosome, and partitioning of cytoplasm all occur during binary fission, while formation of the mitotic spindle does not.
5. Step 5: Conclude that the process which does NOT occur during binary fission in bacteria is the formation of the mitotic spindle.