56) The stroma is the
A) thick fluid enclosed by the inner chloroplast membrane.
B) watery fluid enclosed by the inner membrane of a mitochondrion.
C) space between the inner and outer membranes of a chloroplast.
D) space between the inner and outer membranes of a mitochondrion.
57) Mitochondria differ from chloroplasts in that mitochondria
A) convert light energy from the sun to chemical energy, whereas chloroplasts convert one form
of chemical energy to another.
B) contain three different membrane-bound compartments, whereas chloroplasts contain two.
C) contain membrane folds called cristae, whereas chloroplasts contain disk-like vesicles in
stacks called grana.
D) are not found in plants, whereas chloroplasts are not found in animals.
58) The endosymbiosis hypothesis proposes that
A) two separate cells worked cooperatively and one benefited from the other.
B) a small cell lived inside a larger cell to the benefit of both cells.
C) a large cell engulfed and digested a smaller cell, exposing its enzymes for use by the larger
cell.
D) two cells merged into one cell, improving the enzyme function of the new cell.
59) The endosymbiosis hypothesis is supported by all of the following pieces of evidence except
the fact that
A) mitochondria have circular DNA like prokaryotes.
B) mitochondria lack ribosomes like prokaryotes.
C) chloroplasts have ribosomes like prokaryotes.
D) chloroplasts reproduce through a splitting process like certain prokaryotes.
60) Microfilaments differ from microtubules in that microfilaments
A) are thicker than microtubules.
B) are found only in plants, whereas microtubules are found in both plant and animal cells.
C) are mainly composed of actin, whereas microtubules are composed of tubulin.
D) help to anchor organelles, whereas microtubules primarily function to help cells change shape
and move.
61) Which of the following statements about the cytoskeleton is false?
A) The cytoskeleton helps to support cells.
B) Once laid down, the elements of the cytoskeleton are fixed and remain permanently in place.
C) The cytoskeleton is composed of three types of fibers: microfilaments, microtubules, and
intermediate filaments.
D) The cytoskeleton plays an important role in amoeboid motion.
62) Intermediate filaments
A) guide the movements of chromosomes.
B) surround the nucleus.
C) guide the movements of organelles.
D) support the inner mitochondrial membrane.
63) A drug that interferes with microtubule formation is likely to completely disrupt
A) the amoeboid motion of a cell.
B) the function of lysosomes.
C) contraction of muscle cells.
D) the movements of sperm cells.
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64) Cilia differ from flagella in that
A) cilia contain nine microtubule doublets surrounding a central pair of microtubules, whereas
flagella contain only nine microtubule doublets.
B) the protein filaments of cilia are “naked,” whereas those of flagella are wrapped in an
extension of the cell membrane.
C) cilia are typically more numerous and shorter than flagella.
D) cilia are anchored only in the proteins of the cell membrane, whereas flagella are anchored in
a special structure called the basal body.
65) A basal body is
A) composed of nine microtubule triplets surrounding a central pair of microtubules.
B) similar in structure to centrioles.
C) composed of nine microtubule doublets surrounding a central pair of microtubules.
D) identical in structure to cilia.
66) Dynein feet
A) are present in cilia but not in flagella.
B) are knobs of carbohydrate that are essential to the movement of cilia and flagella.
C) are found on microtubules in cilia and flagella and cause movement by grabbing and pulling
at adjacent microtubule doublets.
D) are the anchoring proteins in basal bodies.
67) A woman is having trouble becoming pregnant. Examination of her partner’s sperm indicates
that dynein feet are missing from the flagella in his sperm cells. A physician explains that this
could interfere with fertility by
A) preventing the sperm from attaching to the egg cell.
B) preventing the sperm from swimming to the egg cell.
C) preventing the sperm from producing enough energy to power swimming.
D) interfering with the attachment of the flagella to the sperm.
68) Most animal cells are
A) surrounded by a cell wall.
B) attached to each other via plasmodesmata.
C) embedded in an extracellular matrix.
D) embedded in a lipid matrix.
69) The extracellular matrix attached to cells via glycoproteins may then bind to ________ in the
plasma membrane.
A) dynein
B) collagen
C) integrins
D) polysaccharides
70) Which of the following would be most affected by a mutation that prevented cells from
forming tight junctions?
A) attachment of cells to the surrounding matrix
B) direct flow of water and small molecules from one cell to another
C) integrity of the inner lining of the digestive tract
D) attachment of the cytoskeleton to the inside of the plasma membrane
71) Skin cells are fastened into strong sheets by
A) basal bodies.
B) anchoring junctions.
C) tight junctions.
D) communicating junctions.
72) It is essential for heart muscle cells to beat in a coordinated fashion. The cell junctions that
would best facilitate this are
A) occluding junctions.
B) anchoring junctions.
C) tight junctions.
D) gap junctions.
73) Which of the following statements about plant cell walls is false?
A) Plant cell walls consist of cellulose fibers embedded in a matrix of polysaccharides and
proteins.
B) Plant cell walls are multilayered structures.
C) Plant cell walls protect plant cells by forming an impermeable layer around the cell.
D) Wood is primarily composed of plant cell walls.
74) Which of the following statements regarding plasmodesmata is false?
A) Plasmodesmata penetrate plant cell walls.
B) Plasmodesmata carry chemical messages between plant cells.
C) Plasmodesmata carry nutrients between plant cells.
D) Plasmodesmata are found in plants as well as some single-celled organisms.
75) Which of the following cell structures are associated with the breakdown of harmful
substances?
A) chloroplasts
B) mitochondria
C) peroxisomes
D) centrioles
76) Which of the following statements regarding cells is false?
A) All cells are enclosed in a membrane that maintains internal conditions different from the
surroundings.
B) All cells have a cell wall.
C) All cells can interconvert forms of energy.
D) All cells have DNA as their genetic material.
77) A child dies following a series of chronic bacterial infections. At the autopsy, the physicians
are startled to see that the child’s white blood cells are loaded with vacuoles containing intact
bacteria. Which of the following explanations could account for this finding?
A) A defect in the Golgi apparatus prevented the cells from processing and excreting the
bacteria.
B) A defect in the rough endoplasmic reticulum prevented the synthesis of the antibodies
(defensive proteins) that would have inactivated the bacteria.
C) A defect in the cell walls of the white blood cells permitted bacteria to enter the cells.
D) A defect in the lysosomes of the white blood cells prevented the cells from destroying
engulfed bacteria.
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4.2 Art Questions
1) According to this figure, which of the following are large enough to see in the light
microscope?
A) atoms
B) proteins
C) viruses
D) mitochondria
2) Which part of the mitochondrion shown enhances its ability to produce ATP by increasing the
surface area of a mitochondrial membrane?
A) structure A
B) structure B
C) structure C
D) structure D
3) Which of these conclusions cannot reasonably be drawn from the graph?
A) Protein production occurs throughout the cell cycle.
B) Increase in ribosomal activity occurs as a cell prepares to divide.
C) Cells export a large amount of protein following cell division.
D) There is always a supply of amino acids in the cell.
4) The graph shows that
A) at any given time there are more cells in G2 than G1.
B) protein used in G1 is recycled to produce protein in S.
C) not all cells at any given stage have the same amount of protein.
D) protein levels in cells remain constant throughout the cell cycle.
5) Which of the following can be concluded from the graph?
A) There are three times as many cells in G2 as there are in G1.
B) Cells in S have 30% more protein than cells in G1.
C) Cells in G2 have three times as much protein as cells in G1.
D) The same proteins are present at each stage but are present in different amounts.
6) Most of the protein measured in the cells was likely synthesized by
A) mitochondria.
B) nucleolus.
C) smooth endoplasmic reticulum.
D) ribosomes.
7) The technique used to produce the data displayed might be useful for a cancer biologist who
wishes to
A) determine whether a drug can prevent cell division.
B) determine the effect of a drug on microtubule assembly.
C) determine the effect of drugs on protein synthesis at various times in the cell cycle.
D) determine the effect of a drug on mitochondrial function.
4.3 Scenario Questions
After reading the paragraph below, answer the questions that follow.
The skin is the body’s largest organ. It’s made up of many different types of cells. Oils, produced
by the sebaceous glands, prevent the skin from drying and splitting. The protein melanin,
produced by melanocytes in the epidermis, protects the skin from the harmful effects of
ultraviolet radiation. Sweat, released through ducts to the skin surface, helps to cool the body.
The types of cells that produce these compounds have different numbers of specific organelles,
depending on their function.
1) Based on their function, you would expect melanocytes in the skin to have a higher than usual
number of
A) lysosomes.
B) chloroplasts.
C) ribosomes.
D) microtubules.
2) The oil from the sebaceous glands is produced by which of the following cell organelles?
A) ribosomes
B) rough endoplasmic reticulum
C) cell membrane
D) smooth endoplasmic reticulum
After reading the paragraph below, answer the questions that follow.
Studies of the endomembrane system often involve the use of a protein that can emit a green
fluorescence (glow). A researcher wants to make a video of cell behavior, so she initially tags the
outer nuclear envelope of a cell with the fluorescent tag and records for several hours. Later, she
sees that the tag is part of a secretory vesicle.
3) What likely happened during the intervening time?
A) The outer membrane of the nucleus broke off and moved the fluorescent tag to the Golgi.
B) The endoplasmic reticulum engulfed the tagged protein and released it in a secretory vacuole.
C) Material from the nucleus, including the tag, was being secreted outside the cell.
D) The tag was seen in the Golgi before being seen in a secretory vacuole.
4) The fluorescent tag likely became incorporated into which of the following organelles during
the video?
A) mitochondria
B) ribosomes
C) endoplasmic reticulum
D) peroxisomes
5) The fluorescent tag likely did not become incorporated into which of the following
organelles?
A) lysosome
B) Golgi
C) microtubules
D) rough ER
6) The ability to stain protein molecules with a fluorescent dye would most clearly allow
researchers to go beyond what they could previously detect with a microscope by allowing them
to
A) detect ribosome activity.
B) detect when DNA is replicating.
C) distinguish a prokaryote from a eukaryote.
D) determine whether a cell had cilia or flagella.