Which of the following statements about microtubules during anaphase is true?

• A. Microtubules remain unchanged in length during anaphase.
• B. Microtubules shorten to pull sister chromatids apart.
• C. Microtubules lengthen to push sister chromatids together.
• D. Microtubules disassemble completely before anaphase begins.

Answer: (B)

Verified step by step guidance

1. Understand the role of microtubules during cell division, specifically in the process of mitosis. Microtubules are part of the cytoskeleton and play a crucial role in separating sister chromatids during anaphase.
2. Recall that anaphase is a stage in mitosis where sister chromatids are pulled apart toward opposite poles of the cell. This movement is facilitated by the shortening of microtubules.
3. Microtubules are dynamic structures that can lengthen and shorten by adding or removing tubulin subunits. During anaphase, microtubules attached to the kinetochores of chromatids shorten, pulling the chromatids apart.
4. Consider the statement: 'Microtubules shorten to pull sister chromatids apart.' This accurately describes the mechanism by which chromatids are separated during anaphase.
5. Evaluate the other statements: 'Microtubules remain unchanged in length during anaphase,' 'Microtubules lengthen to push sister chromatids together,' and 'Microtubules disassemble completely before anaphase begins.' These are incorrect based on the known function of microtubules during anaphase.