Histology and Cell Biology

Cytoskeleton and motility Practice Questions

21 free Cytoskeleton and motility practice questions for the USMLE Step 1, each with the correct answer and a detailed explanation. Open any question below, or take the full set as an interactive quiz.

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All Cytoskeleton and motility questions

21 questions
  1. Q1. Which of the following is NOT one of the three principal filament types of the eukaryotic cytoskeleton?
  2. Q2. Which cytoskeletal filament type is primarily responsible for resisting compressive forces within the cell and serving as tracks for intracellular vesicle tran…
  3. Q3. Which cytoskeletal component is most directly involved in generating protrusive structures like lamellipodia and filopodia during cell migration?
  4. Q4. Which cytoskeletal element is most important for maintaining tensile strength and anchoring organelles, rather than rapid remodeling like microfilaments or mic…
  5. Q5. During mitosis, which cytoskeletal structure is primarily responsible for separating sister chromatids and segregating chromosomes to opposite poles?
  6. Q6. What is the approximate diameter of actin (microfilament) filaments in the cytoskeleton?
  7. Q7. Which motor protein moves cargo toward the minus end of microtubules — i.e., toward the cell center (centrosome)?
  8. Q8. Which cytoskeletal filament is least dynamic (i.e., most stable) under normal conditions, contributing to long-term structural integrity of tissues?
  9. Q9. Which step is NOT directly dependent on actin and myosin-mediated cytoskeletal contraction during cell motility?
  10. Q10. Which cytoskeletal filament is the main structural element of eukaryotic cilia and flagella, enabling their motility?
  11. Q11. What is the role of actin polymerization at the leading edge of a migrating cell?
  12. Q12. Which cytoskeletal element would most likely be disrupted in a disease causing fragility of skin epithelial cells under mechanical stress?
  13. Q13. Which cytoskeletal filaments are most directly involved in cytokinesis (cell division) during cleavage of a dividing cell in animal cells?
  14. Q14. Which statement best captures the dynamic nature of the cytoskeleton in a typical eukaryotic cell?
  15. Q15. Which of the following cytoskeletal processes would most likely be impaired by a toxin that inhibits tubulin polymerization?
  16. Q16. Which class of proteins links cytoskeletal filaments to the plasma membrane or to other cytoskeletal elements to coordinate cellular architecture and signal tr…
  17. Q17. Which of the following motor proteins utilizes ATP to slide along actin filaments and generate contractile force in muscle and nonmuscle cells?
  18. Q18. During directed cell migration, which cytoskeletal filament system and associated dynamics are mainly responsible for establishing cell polarity (front–rear ax…
  19. Q19. Which cytoskeletal alteration would most likely impair endocytosis and exocytosis processes dependent on vesicle transport?
  20. Q20. Which cytoskeletal element and associated molecular motors are primarily responsible for retrograde (toward nucleus) vesicular transport in neurons?
  21. Q21. Which of the following best describes how cytoskeletal dysfunction could contribute to neurodegenerative or muscular diseases?