Question 1

Which of the following best describes the structural polarity of actin filaments?

Accepted Answer

Actin filaments have plus and minus ends, with faster growth at the plus end.

Question 2

A mutation in the gene encoding nuclear lamins is most likely to affect which cellular structure or function?

Accepted Answer

The structural support of the nuclear envelope

Question 3

Which cytoskeletal element is primarily responsible for the separation of chromosomes during mitosis?

Accepted Answer

Microtubules

Question 4

A scientist observes a cell with defective myosin proteins. Which process is most likely to be impaired?

Accepted Answer

Cytokinesis in animal cells

Question 5

Which of the following statements about intermediate filaments is correct?

Accepted Answer

They are composed of various proteins such as keratin and lamins and lack structural polarity.

Question 6

What is the primary function of kinesin motor proteins in eukaryotic cells?

Accepted Answer

Transporting vesicles along microtubules using ATP hydrolysis

Question 7

Which cytoskeletal element is most directly involved in cytoplasmic streaming in plant cells?

Accepted Answer

Actin filaments

Question 8

A patient with progeria has a mutation in a gene encoding a nuclear lamin. Which cellular process is most likely disrupted?

Accepted Answer

Maintenance of nuclear envelope integrity

Question 9

Which of the following best explains the dynamic instability of microtubules?

Accepted Answer

Microtubules rapidly grow and shrink from their plus ends due to GTP hydrolysis.

Question 10

Which of the following is a key difference between eukaryotic and prokaryotic flagella?

Accepted Answer

Eukaryotic flagella are composed of microtubules arranged in a '9+2' axoneme, while prokaryotic flagella are made of flagellin.

Question 11

During vesicle transport in animal cells, which direction does kinesin move along the microtubule?

Accepted Answer

Toward the plus end of the microtubule

Question 12

Which cytoskeletal element is most important for resisting mechanical stress in epithelial cells such as skin?

Accepted Answer

Intermediate filaments (keratin)

Question 13

Which of the following best describes the role of ATP in actin-myosin interactions?

Accepted Answer

ATP hydrolysis provides energy for myosin to move along actin filaments.

Question 14

A cell is observed to have defective centrosomes. Which process is most likely to be affected?

Accepted Answer

Organization and nucleation of microtubules

Question 15

Which of the following equations correctly represents the hydrolysis of ATP by a motor protein such as kinesin?

Accepted Answer

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

Question 16

Which cytoskeletal element is most directly involved in the formation of the contractile ring during animal cell cytokinesis?

Accepted Answer

Actin filaments

Question 17

Which of the following best explains why microtubules are considered dynamic structures?

Accepted Answer

They undergo rapid cycles of growth and shrinkage, a process known as dynamic instability.

Question 18

Which of the following is a function shared by both actin filaments and microtubules?

Accepted Answer

They both provide tracks for motor proteins to move cellular components.

Question 19

A researcher disrupts the function of dynein in a eukaryotic cell. Which process is most likely to be impaired?

Accepted Answer

Bending of cilia and flagella

Question 20

Which of the following best describes the '9+2' arrangement in eukaryotic cilia and flagella?

Accepted Answer

Nine doublets of microtubules surrounding two central microtubules

The Cytoskeleton: Structure and Function Inside the Cell

Guida di studio - Domande di pratica