The smallest cell structure that would most likely be visible with a standard research- grade light microscope is a...
a. mitochondrion
b. microtubule
c. ribosome
d. microfilament
mitochondrion
The advantages of light microscopy over electron microscopy is that...
light microscopy allows one to view dynamic processes in living cells.
In the fractionation of homogenized cells using centrifugation, the primary factor that determines whether a specific cellular component ends up in the supernatant or the pellet is the ...
size and weight of the component
What is the reason that a modern transmission electron microscope (TEM) can resolve biological images to the subnanometer level, as opposed to tens of nanometers achievable for the best super-resolution light microscope?
C) Electron beams have much shorter wavelengths than visible light.
What technique would be most appropriate to use to observe the movements of condensed chromosomes during cell division?
A) standard light microscopy
A newspaper ad for a local toy store indicates that an inexpensive toy microscope available for a small child is able to magnify specimens nearly as much as the more costly microscope available in your college lab. What is the primary reason for the price difference?
The toy microscope magnifies a good deal, but has low resolution and therefore poor quality images.
7) All of the following are part of a prokaryotic cell EXCEPT _____.
D) an endoplasmic reticulum
8) Cell size is limited by _____.
C) surface to volume ratios
Which of the following is a major difference between prokaryotic cells and eukaryotic cells?
B) Eukaryotic cells have more intracellular organelles than prokaryotes.
You have a cube of modeling clay in your hands. Which of the following changes to the shape of this cube of clay will decrease its surface area relative to its volume?
C) Round the clay up into a sphere.
11) Prokaryotes are classified as belonging to two different domains. What are the domains?
B) Bacteria and Archaea
Which structure is common to plant and animal cells?
mitochondrion
13) Which of the following is present in a prokaryotic cell?
Ribosome
14) In a bacterium, we will find DNA in _____.
the nucleoid
Which organelle or structure is absent in plant cells?
centrosomes
What is the function of the nuclear pore complex found in eukaryotes?
A) It regulates the movement of proteins and RNAs into and out of the nucleus.
Which of the following macromolecules leaves the nucleus of a eukaryotic cell through pores in the nuclear membrane?
mRNA
Which of the following statements correctly describes some aspect of protein secretion from prokaryotic cells?
Proteins secreted by prokaryotes are synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane.
Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?
proteins
The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would you most likely expect to be the immediate consequence?
a change in the shape of the nucleus
A cell with a predominance of free ribosomes is most likely _____.
primarily producing proteins in the cytosol
Which organelle often takes up much of the volume of a plant cell?
vacuole
A cell with an extensive area of smooth endoplasmic reticulum is specialized to _____.
synthesize large quantities of lipids
Which structure is NOT part of the endomembrane system?
chloroplast
The Golgi apparatus has a polarity, or sidedness, to its structure
and function. Which of the following statements correctly describes
this polarity?
A) Transport vesicles fuse with one side of the
Golgi and leave from the opposite side.
B) Proteins in the
membrane of the Golgi may be sorted and modified as they move from one
side of the Golgi to the other.
C) Lipids in the membrane of the
Golgi may be sorted and modified as they move from one side of the
Golgi to the other.
D) All of the listed responses correctly
describe polarity characteristics of the Golgi function.
D) All of the listed responses correctly describe polarity characteristics of the Golgi function.
The difference in lipid and protein composition between the membranes
of the endomembrane system is largely determined by the _____.
A)
transportation of membrane lipids among the membranes of the
endomembrane system by small membrane vesicles
B) function of the
Golgi apparatus in sorting and directing membrane components
C)
modification of the membrane components once they reach their final
destination
D) synthesis of different lipids and proteins in each
of the organelles of the endomembrane system
B) function of the Golgi apparatus in sorting and directing membrane components
Which structure is the site of the synthesis of proteins that may be
exported from the cell?
A) rough ER
B) plasmodesmata
C)
Golgi vesicles
D) free cytoplasmic ribosomes
A) rough ER
Tay-Sachs disease is a human genetic abnormality that results in
cells accumulating and becoming clogged with very large, complex,
undigested lipids. Which cellular organelle must be involved in this
condition?
A) the endoplasmic reticulum
B) the Golgi
apparatus
C) the lysosome
D) mitochondrion
C) the lysosome
The liver is involved in detoxification of many poisons and drugs.
Which of the following structures is primarily involved in this
process and, therefore, abundant in liver cells?
A) rough
ER
B) smooth ER
C) Golgi apparatus
D) nuclear envelope
B) smooth ER
Which of the following produces and modifies polysaccharides that
will be secreted?
A) lysosome
B) mitochondrion
C) Golgi
apparatus
D) peroxisome
C) Golgi apparatus
What is the most likely pathway taken by a newly synthesized protein
that will be secreted by a cell?
A) ER → Golgi → nucleus
B)
Golgi → ER → lysosome
C) ER → Golgi → vesicles that fuse with
plasma membrane
D) ER → lysosomes → vesicles that fuse with
plasma membrane
C) ER → Golgi → vesicles that fuse with plasma membrane
Asbestos is a material that was once used extensively in
construction. One risk from working in a building that contains
asbestos is the development of asbestosis caused by the inhalation of
asbestos fibers. Cells will phagocytize asbestos, but are not able to
degrade it. As a result, asbestos fibers accumulate in _____.
A)
mitochondria
B) ribosomes
C) peroxisomes
D) lysosomes
D) lysosomes
Which of the following is NOT true? Both chloroplasts and
mitochondria _____.
A) have their own DNA
B) have multiple
membranes
C) are part of the endomembrane system
D) are
capable of reproducing themselves
C) are part of the endomembrane system
Which organelle is the primary site of ATP synthesis in eukaryotic
cells?
A) lysosome
B) mitochondrion
C) Golgi
apparatus
D) peroxisome
B) mitochondrion
Thylakoids, DNA, and ribosomes are all components found in
_____.
A) chloroplasts
B) mitochondria
C)
lysosomes
D) nuclei
A) chloroplasts
In a plant cell, DNA may be found _____.
A) only in the
nucleus
B) only in the nucleus and chloroplasts
C) in the
nucleus, mitochondria, and chloroplasts
D) in the nucleus,
mitochondria, chloroplasts, and peroxisomes
C) in the nucleus, mitochondria, and chloroplast
In a liver cell detoxifying alcohol and some other poisons, the
enzymes of the peroxisome remove hydrogen from these molecules and
_____.
A) combine the hydrogen with water molecules to generate
hydrogen peroxide
B) use the hydrogen to break down hydrogen
peroxide
C) transfer the hydrogen to the mitochondria
D)
transfer the hydrogen to oxygen molecules to generate hydrogen peroxide
D) transfer the hydrogen to oxygen molecules to generate hydrogen peroxide
The evolution of eukaryotic cells most likely involved _____.
A)
endosymbiosis of an aerobic bacterium in a larger host cell—the
endosymbiont evolved into mitochondria
B) anaerobic archaea
taking up residence inside a larger bacterial host cell to escape
toxic oxygen—the anaerobic bacterium evolved into chloroplasts
C)
an endosymbiotic fungal cell evolving into the nucleus
D)
acquisition of an endomembrane system and subsequent evolution of
mitochondria from a portion of the Golgi
A) endosymbiosis of an aerobic bacterium in a larger host cell—the endosymbiont evolved into mitochondria
Where are proteins produced other than on ribosomes free in the
cytosol or ribosomes attached to the ER?
A) in the extracellular
matrix
B) in the Golgi apparatus
C) in mitochondria
D)
in the nucleolus
C) in mitochondria
Suppose a cell has the following molecules and structures: enzymes,
DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell
from _____.
A) a bacterium
B) an animal but not a
plant
C) nearly any eukaryotic organism
D) a plant but not
an animal
C) nearly any eukaryotic organism
Cyanide binds with at least one molecule involved in producing ATP.
If a cell is exposed to cyanide, most of the cyanide will be found
within the _____.
A) mitochondria
B) peroxisomes
C)
lysosomes
D) endoplasmic reticulum
A) mitochondria
Suppose a young boy is always tired and fatigued, suffering from a
metabolic disease. Which of the following organelles is most likely
involved in this disease?
A) lysosomes
B) Golgi
apparatus
C) ribosomes
D) mitochondria
D) mitochondria
Motor proteins provide for molecular motion in cells by interacting
with what types of cellular structures?
A) membrane proteins of
the inner nuclear envelope
B) free ribosomes and ribosomes
attached to the ER
C) components of the cytoskeleton
D)
cellulose fibers in the cell wall
C) components of the cytoskeleton
Which of the following contain the 9 + 2 arrangement of microtubules,
consisting of nine doublets of microtubules surrounding a pair of
single microtubules?
A) motile cilia and primary (nonmotile)
cilia
B) flagella and motile cilia
C) basal bodies and
primary (nonmotile) cilia
D) centrioles and basal bodies
B) flagella and motile cilia
Vinblastine, a drug that inhibits microtubule polymerization, is used
to treat some forms of cancer. Cancer cells given vinblastine would be
unable to _____.
A) form cleavage furrows during cell
division
B) migrate by amoeboid movement
C) separate
chromosomes during cell division
D) maintain the shape of the nucleus
C) separate chromosomes during cell division.
Amoebae move by crawling over a surface (cell crawling), which
involves _____.
A) growth of actin filaments to form bulges 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) cytoplasmic streaming
A) growth of actin filaments to form bulges in the plasma membrane
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 microfilaments
C) endoplasmic
reticulum
D) motor proteins
D) motor proteins
Cilia and flagella bend because of _____.
A) conformational
changes in ATP that thrust microtubules laterally
B) a motor
protein called radial spokes
C) the quick inward movements of
water by osmosis.
D) a motor protein called dynein
D) a motor protein called dynein
Spherocytosis is a human blood disorder associated with a defective
cytoskeletal protein in the red blood cells (RBCs). What do you
suspect is the consequence of such a defect?
A) abnormally shaped
RBCs
B) an insufficient supply of ATP in the RBCs
C) an
insufficient supply of oxygen-transporting proteins in the
RBCs
D) adherence of RBCs to blood vessel walls, causing plaque formation
A) abnormally shaped RBCs
Cytochalasin D is a drug that prevents actin polymerization. A cell
treated with cytochalasin D will still be able to _____.
A)
divide in two
B) contract muscle fibers
C) extend
pseudopodia
D) move vesicles within a cell
D) move vesicles within a cell
Cells require which of the following to form cilia or
flagella?
A) tubulin
B) laminin
C) actin
D)
intermediate filaments
A) tubulin
Which of the following statements about the cytoskeleton is
true?
A) The cytoskeleton of eukaryotes is a static structure
most resembling scaffolding used at construction sites.
B)
Although microtubules are common within a cell, actin filaments are
rarely found outside of the nucleus.
C) Movement of cilia and
flagella is the result of motor proteins causing microtubules to move
relative to each other.
D) Chemicals that block the assembly of
the cytoskeleton would have little effect on a cell's response to
external stimuli.
Movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other
The cell walls of bacteria, fungi, and plant cells and the
extracellular matrix of animal cells are all external to the plasma
membrane. Which of the following is a characteristic common to all of
these extracellular structures?
A) They must block water and
small molecules to regulate the exchange of matter and energy with
their environment.
B) They must provide a rigid structure that
maintains an appropriate ratio of cell surface area to volume.
C)
They are constructed of polymers that are synthesized in the cytoplasm
and then transported out of the cell.
D) They are composed of a
mixture of lipids and nucleotides.
C) They are constructed of polymers that are synthesized in the cytoplasm and then transported out of the cell.
A mutation that disrupts the ability of an animal cell to add
polysaccharide modifications to proteins would most likely cause
defects in its _____.
A) nuclear matrix and extracellular
matrix
B) mitochondria and Golgi apparatus
C) Golgi
apparatus and extracellular matrix
D) nuclear pores and secretory vesicles
C) Golgi apparatus and extracellular matrix
The extracellular matrix is thought to participate in the regulation
of animal cell behavior by communicating information from the outside
to the inside of the cell via which of the following?
A) gap
junctions
B) the nucleus
C) DNA and RNA
D) integrins
D) integrins
Plasmodesmata in plant cells are most similar in function to which of
the following structures in animal cells?
A) desmosomes
B)
gap junctions
C) extracellular matrix
D) tight junctions
B) gap junctions
Ions can travel directly from the cytoplasm of one animal cell to the
cytoplasm of an adjacent cell through _____.
A)
plasmodesmata
B) tight junctions
C) desmosomes
D) gap junctions
D) gap junctions
In plant cells, the middle lamella _____.
A) allows adjacent
cells to adhere to one another
B) prevents dehydration of
adjacent cells
C) maintains the plant's circulatory
system
D) allows for gas and nutrient exchange among adjacent cells
A) allows adjacent cells to adhere to one another
Where would you expect to find tight junctions?
A) in the
epithelium of an animal's stomach
B) between the smooth
endoplasmic reticulum and the rough endoplasmic reticulum
C)
between plant cells in a woody plant
D) in the plasma membrane of prokaryotes
A) in the epithelium of an animal's stomach
H. V. Wilson worked with sponges to gain some insight into exactly
what was responsible for holding adjacent cells together. He exposed
two species of differently pigmented sponges to a chemical that
disrupted the cell-cell interaction (cell junctions), and the cells of
the sponges dissociated. Wilson then mixed the cells of the two
species and removed the chemical that caused the cells to dissociate.
Wilson found that the sponges reassembled into two separate species.
The cells from one species did not interact or form associations with
the cells of the other species. How do you explain the results of
Wilson's experiments?
A) The two species of sponge had different
enzymes that functioned in the reassembly process.
B) The
molecules responsible for cell-cell adhesion (cell junctions) were
irreversibly destroyed during the experiment.
C) The molecules
responsible for cell-cell adhesion (cell junctions) differed between
the two species of sponge.
D) One cell functioned as the nucleus
for each organism, thereby attracting only cells of the same pigment.
C) The molecules responsible for cell-cell adhesion (cell junctions) differed between the two species of sponge.
Gaucher disease is the most common of lipid storage diseases in
humans. It is caused
by a deficiency of an enzyme necessary for
lipid metabolism. This leads to a collection of
fatty material in
organs of the body including the spleen, liver, kidneys, lungs, brain,
and
bone marrow.
Using your knowledge of the structure of
eukaryotic cells, identify the statement below
that best explains
how internal membranes and the organelles of cells would be
involved
in Gaucher disease.
A) The mitochondria are most
likely defective and do not produce adequate amounts of
ATP
needed for cellular respiration.
B) The rough endoplasmic
reticulum contains too many ribosomes which results in
an
overproduction of the enzyme involved in carbohydrate
catalysis.
C) The lysosomes lack sufficient amounts of enzymes
necessary for the metabolism of
lipids.
D) The Golgi
apparatus produces vesicles with faulty membranes that leak their
contents
into the cytoplasm of the cell.
C) The lysosomes lack sufficient amounts of enzymes necessary for the
metabolism of
lipids.