[Campbell Biology P.163] Which of the following statements about microtubules is FALSE? | Practice Question

Which of the following statements about microtubules is FALSE?

  • A: Microtubules are hollow rods constructed from globular proteins called tubulins.
  • B: A tubulin protein is a dimer consisting of α-tubulin and β-tubulin polypeptides.
  • C: The "plus end" of a microtubule is where tubulin proteins can only be added, but not released.
  • D: Microtubules play roles in cell shaping, organelle movement, and chromosome separation during cell division.

Explanation

Microtubules are composed of tubulin dimers and are involved in cell shape, intracellular transport, and chromosome segregation. The 'plus end' of a microtubule is where both the 'on' and 'off' rates of tubulin dimers are much higher, allowing for rapid growth and shrinkage, not just addition.