MCB 150 EXAM STUDY GUIDE EXAMS SET
COMPLETE QUESTIONS AND ANSWERS
2026 VIEW AHEAD EXAM.
⫸ Treatment of a cell with the drug Colchicine will:
A. promote microtubule depolymerization because the
colchicine will bind the microtubule ends.
B. stabilize microtubule length because colchicine will bind the
microtubule ends.
C. promote microtubule depolymerization because the effective
concentration of tubulin will be too low to sustain polymerization.
D. stop microtubule depolymerization because the free tubulin will
bind the colchicine.
E. promote microtubule polymerization because the colchicine will
bind the microtubule ends. Answer: C. promote microtubule
depolymerization because the effective concentration of tubulin will
be too low to sustain polymerization.
⫸ Identify if each of the following statements are true or false.
Choices: True, False.
1. Microtubules and tubulin building blocks both have polarity.
2. If the concentration of GTP-bound tubulin is increased,
depolymerization is more likely to occur.
,3. The addition of ATP to tubulin will increase the concentration of
ATP bound tubulin and the microtubule will polymerize.
4. Assembly and disassembly of microtubules is typically fastest at
the plus end in a living cell. Answer: 1. True.
2. False. If the concentration of GTP-bound tubulin is increased,
polymerization is more likely to occur.
3. False. The addition of GTP to tubulin will increase the
concentration of GTP-bound tubulin and the microtubule will
polymerize.
4. True. (since the minus end is bound to the MTOC)
⫸ Which of the following statements is TRUE?
A. Axons and dendrites are examples of microvilli.
B. Axons and dendrites are important for the motility of nerve cells.
C. Microtubules are found in a 9+2 pattern in axons but not dendrites.
D. Axons and dendrites are anchored in the centrosome of nerve cells.
E. Axons and dendrites are the cytoplasmic extensions of nerve cells.
Answer: E. Axons and dendrites are the cytoplasmic extensions of
nerve cells.
Axons are not the same as axonemes.
⫸ Which of the following proteins is responsible for the movements
of cilia?
A. Kinesin
B. G-actin
C. Myosin
,D. F-actin
E. Dynein Answer: E. Dynein
⫸ From where do microtubules most specifically originate in an
animal cell?
A. Centrioles
B. Cytoplasm
C. The cell
D. Centromere
E. Pericentriolar material Answer: E. Pericentriolar material
Microtubules emanate from the PCM.
⫸ Identify whether each of the following statements about
microtubules is true or false.
Choices: True, False.
1. Both the alpha and the beta subunit of the microtubules have a GTP
binding site.
2. Microtubules are the largest of the cytoskeletal elements, made up
of 25 protofilaments.
3. In a microtubule, the rate of polymerization in vitro is typically
faster at the plus end.
4. Assembly and disassembly is normally fastest at the plus end in
vivo. Answer: 1. True.
2. False. Microtubules are the largest of the cytoskeletal elements,
made up of 13 protofilaments.
3. True.
, 4. True.
⫸ The behavior in which a microtubule alternates between periods of
growth and shrinkage is most accurately called:
A. recycling.
B. dynamic instability.
C. cytoplasmic streaming.
D. an equilibrium state.
E. treadmilling. Answer: B. dynamic instability.
⫸ The beating of cilia and flagella occurs by means of _______-
based _______.
A. myosin; microtubule contraction
B. dynein; microtubule sliding
C. dynein; microtubule contraction
D. kinesin; microtubule sliding
E. myosin; microfilament sliding Answer: B. dynein; microtubule
sliding
⫸ Cytoplasmic dynein plays a key role in the positioning of which
organelle?
A. Mitochondrion
B. Chloroplast
C. Lysosome
D. Golgi apparatus
COMPLETE QUESTIONS AND ANSWERS
2026 VIEW AHEAD EXAM.
⫸ Treatment of a cell with the drug Colchicine will:
A. promote microtubule depolymerization because the
colchicine will bind the microtubule ends.
B. stabilize microtubule length because colchicine will bind the
microtubule ends.
C. promote microtubule depolymerization because the effective
concentration of tubulin will be too low to sustain polymerization.
D. stop microtubule depolymerization because the free tubulin will
bind the colchicine.
E. promote microtubule polymerization because the colchicine will
bind the microtubule ends. Answer: C. promote microtubule
depolymerization because the effective concentration of tubulin will
be too low to sustain polymerization.
⫸ Identify if each of the following statements are true or false.
Choices: True, False.
1. Microtubules and tubulin building blocks both have polarity.
2. If the concentration of GTP-bound tubulin is increased,
depolymerization is more likely to occur.
,3. The addition of ATP to tubulin will increase the concentration of
ATP bound tubulin and the microtubule will polymerize.
4. Assembly and disassembly of microtubules is typically fastest at
the plus end in a living cell. Answer: 1. True.
2. False. If the concentration of GTP-bound tubulin is increased,
polymerization is more likely to occur.
3. False. The addition of GTP to tubulin will increase the
concentration of GTP-bound tubulin and the microtubule will
polymerize.
4. True. (since the minus end is bound to the MTOC)
⫸ Which of the following statements is TRUE?
A. Axons and dendrites are examples of microvilli.
B. Axons and dendrites are important for the motility of nerve cells.
C. Microtubules are found in a 9+2 pattern in axons but not dendrites.
D. Axons and dendrites are anchored in the centrosome of nerve cells.
E. Axons and dendrites are the cytoplasmic extensions of nerve cells.
Answer: E. Axons and dendrites are the cytoplasmic extensions of
nerve cells.
Axons are not the same as axonemes.
⫸ Which of the following proteins is responsible for the movements
of cilia?
A. Kinesin
B. G-actin
C. Myosin
,D. F-actin
E. Dynein Answer: E. Dynein
⫸ From where do microtubules most specifically originate in an
animal cell?
A. Centrioles
B. Cytoplasm
C. The cell
D. Centromere
E. Pericentriolar material Answer: E. Pericentriolar material
Microtubules emanate from the PCM.
⫸ Identify whether each of the following statements about
microtubules is true or false.
Choices: True, False.
1. Both the alpha and the beta subunit of the microtubules have a GTP
binding site.
2. Microtubules are the largest of the cytoskeletal elements, made up
of 25 protofilaments.
3. In a microtubule, the rate of polymerization in vitro is typically
faster at the plus end.
4. Assembly and disassembly is normally fastest at the plus end in
vivo. Answer: 1. True.
2. False. Microtubules are the largest of the cytoskeletal elements,
made up of 13 protofilaments.
3. True.
, 4. True.
⫸ The behavior in which a microtubule alternates between periods of
growth and shrinkage is most accurately called:
A. recycling.
B. dynamic instability.
C. cytoplasmic streaming.
D. an equilibrium state.
E. treadmilling. Answer: B. dynamic instability.
⫸ The beating of cilia and flagella occurs by means of _______-
based _______.
A. myosin; microtubule contraction
B. dynein; microtubule sliding
C. dynein; microtubule contraction
D. kinesin; microtubule sliding
E. myosin; microfilament sliding Answer: B. dynein; microtubule
sliding
⫸ Cytoplasmic dynein plays a key role in the positioning of which
organelle?
A. Mitochondrion
B. Chloroplast
C. Lysosome
D. Golgi apparatus
