Question

Which of the following statements about the cytoskeleton is TRUE? A. All eucaryotic cells have actin, microtubules, and intermediate filaments in their cytoplasm. B. The cytoskeleton provides a rigid and unchangeable structure important for the shape of the cell. C. The three cytoskeletal filaments perform distinct tasks in the cell and act completely independently of one another. D. Actin filaments and microtubules have an inherent polarity, with a plus end that grows slower than the minus end. E. Protein monomers of cytoskeletons are held together with non-covalent bonds form filaments or tubules.

Answer 1

The true statement about the cytoskeleton is D. Actin filaments and microtubules have an inherent polarity, with a plus end that grows slower than the minus end.

Step-by-step explanation:

Option D accurately describes the inherent polarity of actin filaments and microtubules. Actin filaments have a plus end where polymerization occurs more rapidly than at the minus end. Similarly, microtubules have a plus end where tubulin subunits are added more quickly compared to the minus end. This polarity is crucial for cellular processes like intracellular transport and cell division.

The other options are incorrect: option A is false as not all eukaryotic cells have intermediate filaments, option B is false as the cytoskeleton is dynamic and can undergo changes in structure, option C is false as the cytoskeletal filaments often interact and cooperate, and option E is false as cytoskeletal filaments involve covalent bonds between monomers.

Option D is the answer.