Which structure is responsible for separating sister chromatids during mitosis?

• A. Spindle fibers
• B. Mitochondria
• C. Nucleolus
• D. Golgi apparatus

Answer: (A)

Verified step by step guidance

1. Understand the context of the question: Mitosis is the process of cell division where a single cell divides into two identical daughter cells. During this process, sister chromatids (identical copies of a chromosome) are separated to ensure each daughter cell receives the correct genetic material.
2. Identify the key players in mitosis: The spindle fibers are part of the mitotic spindle, a structure made of microtubules that plays a crucial role in separating sister chromatids during mitosis.
3. Eliminate incorrect options: Mitochondria are responsible for energy production, the nucleolus is involved in ribosome synthesis, and the Golgi apparatus is responsible for packaging and transporting proteins. None of these structures are involved in separating sister chromatids.
4. Focus on the correct structure: Spindle fibers attach to the centromeres of sister chromatids via a protein complex called the kinetochore. They then pull the chromatids apart during anaphase of mitosis.
5. Conclude the reasoning: Based on the function of spindle fibers in separating sister chromatids, the correct answer is 'Spindle fibers.'