[Campbell Biology P.289] Which of the following statements about the mitotic spindle is corr... | Practice Question

Which of the following statements about the mitotic spindle is correct according to the provided text?

  • A: The mitotic spindle is primarily composed of actin filaments and associated proteins.
  • B: Spindle microtubules shorten by incorporating more tubulin subunits.
  • C: The assembly of spindle microtubules in animal cells begins at the centrosome.
  • D: Centrioles are essential structures in all cells for forming the mitotic spindle.

Explanation

The text states: 'In animal cells, the assembly of spindle microtubules starts at the centrosome...'. It also clarifies that the spindle is made of microtubules, not actin filaments, and that microtubules shorten by losing subunits. Furthermore, centrioles are noted as not essential for spindle formation and are absent in plant cells.