What structure(s) allow chromosomes to separate and move during mitosis?

• A. Cell membrane
• B. Spindle fibers
• C. Ribosomes
• D. Nucleolus

Answer: (B)

Verified step by step guidance

1. Understand the process of mitosis: Mitosis is a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus. It involves several stages: prophase, metaphase, anaphase, and telophase.
2. Identify the role of spindle fibers: During mitosis, spindle fibers are crucial for the separation of chromosomes. They form a structure known as the mitotic spindle, which is responsible for pulling apart the sister chromatids and ensuring they move to opposite poles of the cell.
3. Examine the formation of spindle fibers: Spindle fibers are composed of microtubules, which are dynamic structures that can rapidly assemble and disassemble. They originate from the centrosomes, which are located at opposite ends of the cell.
4. Explore the function of spindle fibers in chromosome movement: During anaphase, the spindle fibers shorten, pulling the sister chromatids apart toward the centrosomes. This ensures that each daughter cell receives an identical set of chromosomes.
5. Differentiate spindle fibers from other cell structures: While the cell membrane, ribosomes, and nucleolus have important roles in the cell, they do not directly participate in the movement of chromosomes during mitosis. Spindle fibers are specifically designed for this task.