Q: Which equation best represents the energy conversion used by microtubule motor proteins during intracellular transport?

$$\mathrm{ATP} \rightarrow \mathrm{ADP} + \mathrm{P_i} + \text{energy}$$

Q: Which equation best represents the force generated by actin-myosin interaction during muscle contraction?

$$\text{Actin} + \text{Myosin} + \mathrm{ATP} \rightarrow \text{Actin-Myosin complex} + \mathrm{ADP} + \mathrm{P_i}$$

Question 1

Which of the following statements best describes the primary function of the cytoskeleton in eukaryotic cells?

Accepted Answer

It provides mechanical support, organizes cell structures, and facilitates cell activities such as motility and division.

Question 2

Which cytoskeletal component is primarily responsible for resisting tension and stabilizing cell structure, especially in the outer layer of skin cells?

Accepted Answer

Intermediate filaments

Question 3

Microtubules are composed of which protein subunits?

Accepted Answer

Alpha-tubulin and beta-tubulin

Question 4

During cell division, spindle fibers are formed from which cytoskeletal structure, and what is their main function?

Accepted Answer

Microtubules; they separate chromosomes to opposite poles

Question 5

Which motor protein moves toward the plus end of microtubules, and what energy source does it use?

Accepted Answer

Kinesin; uses ATP

Question 6

A patient with a genetic defect in connexin proteins would most likely have problems with which type of cell junction, and what is a possible physiological consequence?

Accepted Answer

Gap junctions; impaired electrical signaling in heart muscle

Question 7

Which equation best represents the energy conversion used by microtubule motor proteins during intracellular transport?

Accepted Answer

$$\mathrm{ATP} ightarrow \mathrm{ADP} + \mathrm{P_i} + 	ext{energy}$$

Question 8

Which cytoskeletal element is most directly involved in muscle contraction, and what protein does it interact with?

Accepted Answer

Actin filaments; interacts with myosin

Question 9

Which of the following best explains why tight junctions are critical in the epithelial lining of the intestines?

Accepted Answer

They prevent leakage of digestive enzymes and nutrients between cells.

Question 10

A researcher observes that a cell is unable to move its organelles efficiently. Which cytoskeletal structure and associated protein are most likely defective?

Accepted Answer

Microtubules and kinesin

Question 11

Which cell junction is most important for preventing the passage of molecules between adjacent cells in the kidney tubules?

Accepted Answer

Tight junctions

Question 12

Which cytoskeletal element is the thickest, and what is its approximate diameter?

Accepted Answer

Microtubules; 25 nm

Question 13

Which of the following is a unique feature of plasmodesmata in plant cells?

Accepted Answer

They allow direct cytoplasmic exchange between adjacent cells.

Question 14

Which of the following best describes the arrangement of microtubules in a typical motile cilium?

Accepted Answer

A 9+2 pattern: nine doublets surrounding two central singlets

Question 15

Which cell junction is primarily responsible for strong mechanical attachment between cardiac muscle cells, allowing the heart to expand and contract?

Accepted Answer

Adherens junctions

Question 16

A mutation in the gene encoding keratin would most likely affect which cytoskeletal structure and what tissue?

Accepted Answer

Intermediate filaments; skin

Question 17

Which of the following is NOT a function of the cytoskeleton?

Accepted Answer

Synthesizing DNA

Question 18

Which equation best represents the force generated by actin-myosin interaction during muscle contraction?

Accepted Answer

$$	ext{Actin} + 	ext{Myosin} + \mathrm{ATP} ightarrow 	ext{Actin-Myosin complex} + \mathrm{ADP} + \mathrm{P_i}$$

Question 19

Which of the following cell junctions is most directly involved in allowing ions and small molecules to pass freely between adjacent cells in heart muscle?

Accepted Answer

Gap junctions

14-The Cytoskeleton and Cell Junctions: Structure, Function, and Types

Study Guide - Practice Questions

Study Guide - Flashcards