Spring 2011 Bio 1100 Sec03 Quiz 5 Key (blackboard quiz 3)
1. Suppose that the plasma membrane around a flagellum is opened to reveal the axoneme inside. The dynein
sidearms between the peripheral microtubule doublets are then removed by chemical treatment. ATP is then
added. What is the expected observation?
A. The axoneme will elongate or grow in size.
B. There will be normal bending of the flagellum.
C. There will be no movement, since the plasma membrane is not present.
D. There will be no movement, because the ability to use ATP is lost.
2. What can you infer about high-molecular-weight proteins that cannot be transported into the nucleus?
A. They are foreign proteins. B. They lack nuclear localization signals (NLS).
C. They are defective proteins. D. They have been tagged for destruction.
3. What is the function of the nuclear pore complex?
A. It regulates movement of materials across the nuclear envelope.
B. It assembles ribosomes from raw materials that are synthesized in the nucleus.
C. It synthesizes components of the endomembrane system.
D. It synthesizes and repairs DNA.
4. Scientists found that polypeptides that are normally synthesized in the endoplasmic reticulum are about 20
amino acids longer when they are synthesized by ribosomes not attached to the endoplasmic reticulum. What
is/are possible explanations for the greater length of these polypeptides?
A. The ribosomes that function as free ribosomes function differently than the ribosomes that are
attached to the endoplasmic reticulum.
B. The 20 amino acids serve as a signal sequence that directs the forming polypeptide to the
endoplasmic reticulum, where they are cleaved off during processing.
C. The 20-amino-acid sequence helps the endoplasmic reticulum package these proteins for shipping to
the Golgi.
D. The protein has a different function in the cytosol than in the endoplasmic reticulum.
5. Researchers tried to explain how vesicular transport occurs in cells by attempting to assemble the transport
components. They set up microtubular tracks along which vesicles could be transported, and they added vesicles
and ATP (because they knew the transport process requires energy). Yet, when they put everything together,
there was no movement or transport of vesicles. What were they missing?
A. an axon B. contractile filaments C. motor proteins D. rough endoplasmic reticulum
6. Amoeba move by crawling over a surface (amoeboid movement). Which one of the following processes is part
of amoeboid movement?
A. polymerization or extension of actin filaments to form pseudopodia or “false feet” in the plasma
membrane
B. setting up microtubule extensions that vesicles can follow in the movement of cytoplasm
C. reinforcing the pseudopod with intermediate filaments
D. none of the above are plausible answers.
