Which of the following microtubules do not attach to chromosomes?

• A. Kinetochore
• B. Chromosomal
• C. Polar

Answer: (C)

Verified step by step guidance

1. Understand the role of microtubules in cell division: Microtubules are part of the cytoskeleton and play a crucial role in mitosis and meiosis by forming the mitotic spindle, which helps segregate chromosomes into daughter cells.
2. Identify the types of microtubules involved in mitosis: There are three main types of microtubules in the mitotic spindle: kinetochore microtubules, polar microtubules, and astral microtubules.
3. Define kinetochore microtubules: These microtubules attach to the kinetochores, which are protein structures on the chromosome's centromere, and are responsible for pulling the chromosomes apart during cell division.
4. Define polar microtubules: These microtubules extend from the spindle poles and overlap at the cell's equator. They do not attach to chromosomes but instead help push the spindle poles apart, aiding in cell elongation.
5. Conclude which microtubules do not attach to chromosomes: Based on the definitions, polar microtubules do not attach to chromosomes, unlike kinetochore microtubules, which directly interact with the chromosomes.