All of the following occur during mitosis except:

• A. Condensation of chromosomes
• B. Separation of sister chromatids
• C. Pairing of homologous chromosomes
• D. Formation of the mitotic spindle

Answer: (C)

Verified step by step guidance

1. Understand the process of mitosis: Mitosis is a type of cell division that results in two genetically identical daughter cells. It involves several key steps: prophase, metaphase, anaphase, and telophase.
2. Review the events that occur during mitosis: Condensation of chromosomes happens during prophase, where chromosomes become visible and compact. Separation of sister chromatids occurs during anaphase, where chromatids are pulled apart to opposite poles. Formation of the mitotic spindle occurs during prophase and metaphase, where spindle fibers organize and attach to chromosomes.
3. Clarify the concept of homologous chromosomes: Homologous chromosomes are pairs of chromosomes (one from each parent) that are similar in structure and gene content. Pairing of homologous chromosomes occurs during meiosis, specifically in prophase I, not mitosis.
4. Compare mitosis and meiosis: Mitosis is focused on the division of a single cell into two identical cells, while meiosis involves the pairing of homologous chromosomes to create genetic diversity in gametes. This distinction helps identify that pairing of homologous chromosomes is exclusive to meiosis.
5. Conclude that the correct answer is 'Pairing of homologous chromosomes,' as this event does not occur during mitosis but is a characteristic of meiosis.