Chapter 6 Biology

Which of the following statements best explains how a modern transmission electron microscope (TEM) can achieve a resolution of about 2.0 nanometers, whereas a standard light microscope has a maximum resolution of about 200 nanometers? a. TEMs utilize much higher quality glass lenses than those found in light microscopes. b. Staining with atoms of heavy metal provides higher contrast that the colored dyes used in light microscopy. c. Specimens visualized by TEM are much thicker than those observed by light microscopy. d. The wavelengths of electron beams are much shorter than the wavelengths of visible light.

d. The wavelengths of electron beams are much shorter than the wavelengths of visible light.

Cyanide binds to at least one molecule involved in producing ATP. In a cell exposed to cyanide, most of the cyanide will be in ________. a. mitochondria b. ribosomes c. peroxisomes d. lysosomes

a. mitochondria

Which structure is part of the endomembrane system? a. mitochondrion b. Golgi apparatus c.chloroplast d. centrosome

b. Golgi apparatus

The liver is involved in detoxification of many poisons and drugs. Which of the following structures is abundant in liver cells and primarily responsible for detoxification processes? a. rough endoplasmic reticulum b. smooth endoplasmic reticulum c. Golgi apparatus d. nuclear envelope

b. smooth endoplasmic reticulum

Which of the following is the most appropriate technique for observing the movements of condensed chromosomes during cell division? a. a using a magnifying glass b. standard light microscopy c. scanning electron microscopy d. transmission electron microscopy

b. standard light microscopy

A young child who suffers from a metabolic disease is always tired and fatigued. Which of the following organelles is most likely malfunctioning in this disease? a. lysosomes b.Golgi apparatus c. mitochondria d. smooth endoplasmic reticulum

c. mitochondria

Movement of amoebae across a surface requires which of the following activities by components of the cytoskeleton? a. assembly of actin filaments to form bulges in the plasma membrane b. assembly of microtubule extensions that vesicles can follow in the direction of movement c. reinforcement of the pseudopod with intermediate filaments d. localized contractions driven by myosin and microtubules

a. assembly of actin filaments to form bulges in the plasma membrane

Which of the following is the smallest biological structure that would most likely be visible with a standard research-grade light microscope? a. chloroplast b. microfilament c. ribosome d.human cheek cell

a. chloroplast

A mutation that disrupts the ability of an animal cell to add polysaccharide modifications to proteins would most likely cause defects in which of the following structural elements? a. extracellular matrix b. intermediate filaments c. microfilaments d.microtubules

a. extracellular matrix

Certain animal cells normally have well-defined spherical nuclei when observed by light microscopy. Cells with a genetic defect have irregularly-shaped nuclei. Which of the following cytoskeletal elements is most likely affected by this genetic defect? a. intermediate filaments b. microfilaments c. microtubules d.myosin proteins

a. intermediate filaments

A cell with a predominance of rough endoplasmic reticulum is most likely involved in which of the following processes? a. producing large quantities of proteins for secretion b. producing large quantities of proteins in the cytosol c.producing large quantities of carbohydrates to assemble an extensive cell wall matrix d. producing large quantities of carbohydrates for storage in the vacuole

a. producing large quantities of proteins for secretion

Disruption of nuclear pore complexes in a eukaryotic cell will most likely interfere with the transport of which of the following molecules into the nucleus? a. ribosomal proteins b. mRNAs c. rRNAs d. phospholipids

a. ribosomal proteins

Based on data from the table above, which of the following statements best explains which cell will be able to eliminate wastes most efficiently? a. Cell 1 because it has the smallest volume and will not produce as much waste as the other cells. b. Cell 2 because it has the highest ratio of surface area to volume, which facilitates the exchange of materials between a cell and its environment. c. Cell 3 because it has the largest surface area, which will enable it to eliminate its wastes most efficiently. d. Cell 3 because it has the greatest volume to handle the greatest amount of waste.

b. Cell 2 because it has the highest ratio of surface area to volume, which facilitates the exchange of materials between a cell and its environment.

Which of the following statements best describes some aspect of protein secretion from prokaryotic cells? a. Prokaryotes cannot secrete proteins because they lack an endomembrane system. b. Proteins secreted by prokaryotes are likely synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane. c.The mechanism of protein secretion in prokaryotes is probably the same as that in eukaryotes. d. Prokaryotes cannot secrete proteins because they lack rough endoplasmic reticulum.

b. Proteins secreted by prokaryotes are likely synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane.

A characteristic 9 + 2 arrangement of microtubules, consisting of nine doublet microtubules surrounding a pair of single microtubules describes the ultrastructure of which of the following cellular structures? a. bacterial flagella b. eukaryotic flagella and motile cilia c. eukaryotic flagella, motile cilia, and nonmotile cilia d.centrioles and basal bodies

b. eukaryotic flagella and motile cilia

Which of the following is present in a prokaryotic cell? a. mitochondrion b. ribosome c.nuclear envelope d. chloroplast

b. ribosome

Which of the following structures are found in plant, animal, and bacterial cells? a. mitochondria b. ribosomes c. chloroplasts d. lysosomes

b. ribosomes

Peroxisomes in liver cells detoxify alcohol by removing hydrogen atoms and combining them with which of the following molecules? a. with water molecules to generate hydrogen peroxide b. with oxygen molecules to generate hydrogen peroxide c. with hydrogen peroxide to generate oxygen d. with hydrogen peroxide to generate oxygen and water

b. with oxygen molecules to generate hydrogen peroxide

Which of the following pairs of organism groups consist solely of prokaryotic cells? a. Bacteria and Eukarya b.Bacteria and Archaea c. Archaea and fungi d. Bacteria and protists

b.Bacteria and Archaea

Which of the following structures is independent of the endomembrane system in eukaryotic cells? a. nuclear envelope b.chloroplast c.Golgi apparatus d.plasma membrane

b.chloroplast

Disruption of the function of which of the following organelles would result in a dramatic decrease in ATP synthesis in eukaryotic cells? a. lysosome b.mitochondrion c. Golgi apparatus d. peroxisome

b.mitochondrion

Which of the following statements best describes some aspect of cytoskeleton structure or function in eukaryotic cells? a. The cytoskeleton 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.

c. Movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other.

If you are provided with a cube of modeling clay, which of the following changes to the shape of this cube will decrease its surface area relative to its volume? a. Cut the cube into eight smaller cubes. b.Flatten the cube into a pancake shape. c. Round the clay up into a sphere. d.Stretch the cube into a long, shoebox shape.

c. Round the clay up into a sphere.

Gaucher disease is the most common genetic disorder affecting lipid storage in humans. The disease is caused by deficiency of an enzyme necessary for the breakdown of lipids, which leads to the accumulation of fatty material in organs of the body including the spleen, liver, kidneys, lungs, brain, and bone marrow. Which of the following statements provides the most plausible explanation for how organelles are impacted by Gaucher disease. a. The mitochondria are most likely defective and do not produce adequate amounts of ATP needed for lipid metabolism. b. The rough endoplasmic reticulum most likely contains excess ribosomes, which results in overproduction of the enzyme involved in lipid breakdown. c. The lysosomes most likely lack sufficient amounts of the enzymes necessary for lipid breakdown. d. The Golgi apparatus most likely produces vesicles with defective membranes, which fail to be transported to the plasma membrane for secretion.

c. The lysosomes most likely lack sufficient amounts of the enzymes necessary for lipid breakdown.

When H. V. Wilson exposed two species of differently pigmented sponges to a chemical that disrupted intercellular junctions, the cells of the sponges dissociated. Wilson then removed the chemical that caused dissociation and mixed the cells of the two species. He found that the sponges reassembled and that the cells from one species did not interact or form associations with the cells of the other species. Which of the following statements provides the most plausible explanation for the results of this experiment? 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 an organizer for each organism, thereby attracting only cells of the same species.

c. The molecules responsible for cell-cell adhesion (cell junctions) differed between the two species of sponge.

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 characteristics is 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 materials that are synthesized in the cytoplasm and then transported out of the cell for assembly. d. They are composed of a mixture of lipids and nucleotides.

c. They are constructed of materials that are synthesized in the cytoplasm and then transported out of the cell for assembly.

Which of the following microscopy techniques is best suited for visualizing protein complexes in their cellular environments without the use of preservatives? a. standard light microscopy b. scanning electron microscopy c. cryo-electron microscopy d. transmission electron microscopy

c. cryo-electron microscopy

Which of the following statements describes a major advantage of light microscopy over electron microscopy? a. light microscopy provides higher magnification than electron microscopy b. light microscopy provides higher resolution than electron microscopy c. light microscopy allows the visualization of dynamic processes in living cells d. light microscopy provides visualization of the topography of cell surfaces

c. light microscopy allows the visualization of dynamic processes in living cells

Disruption of nuclear pore complexes in a eukaryotic cell will most likely interfere with the transport of which of the following molecules out of the nucleus? a. DNA b. amino acids c. mRNA d. phospholipids

c. mRNA

Which of the following structures form cytoplasmic channels that connect adjacent plant cells through the cell walls? a. desmosomes b. gap junctions c. plasmodesmata d. tight junctions

c. plasmodesmata

Which of the following is the most appropriate technique for observing the three-dimensional structure and organization of microvilli on an intestinal cell? a. a using a magnifying glass b. standard light microscopy c. scanning electron microscopy d. transmission electron microscopy

c. scanning electron microscopy

Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells treated with vinblastine would most likely be unable to perform which of the following cellular functions? 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

Which of the following parameters is most likely to limit the maximum size of a cell? a.the absence of a nucleus b.the number of mitochondria in the cytoplasm c. the ratio of surface area to volume of cytoplasm d.the volume of the endomembrane system

c. the ratio of surface area to volume of cytoplasm

Motor proteins provide for molecular motion in cells by interacting with which of the following 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 areas in bacterial cells best describes where chromosomal DNA is generally localized? a. in a membrane-enclosed nucleus b. in mitochondria c.in the nucleoid d.associated with ribosomes

c.in the nucleoid

Which of the following structures is common to plant and animal cells? a. chloroplast b.central vacuole c.mitochondrion d.centriole

c.mitochondrion

Which structure is common to plant and animal cells? a. chloroplast b. central vacuole c.mitochondrion d. centriole

c.mitochondrion

A particular cell contains the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. Based on this composition, it could be a cell from which of the following organisms? a. a bacterium, but not a eukaryote b.an animal, but not a plant c.nearly any eukaryotic organism d.a plant, but not an animal

c.nearly any eukaryotic organism

A newly synthesized protein destined for secretion from a eukaryotic cell will generally follow which of the pathways listed below? a. rough ER → Golgi → transport vesicle → nucleus b.Golgi → rough ER → lysosome → transport vesicle → plasma membrane c.rough ER → Golgi → transport vesicle → plasma membrane d. rough ER → lysosome → transport vesicle → plasma membrane

c.rough ER → Golgi → transport vesicle → plasma membrane

Which of the following statements describes a primary function of integrins? a. connecting intermediate filaments to microtubules involved in vesicular transport b. linking the primary and secondary cell walls in plants c.transmitting signals from the extracellular matrix to the cytoskeleton d.transmitting chemical signals from the Golgi apparatus to the plasma membrane

c.transmitting signals from the extracellular matrix to the cytoskeleton

Bending of cilia and flagella results from which of the following activities? a. conformational changes in ATP that thrust microtubules laterally b. conformational changes in microfilaments c. contraction by myosin d. conformational changes in a motor protein called dynein

d. conformational changes in a motor protein called dynein

Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through which of the following structures? a. plasmodesmata b. tight junctions c. desmosomes d. gap junctions

d. gap junctions

If plant cells are grown on media containing radioactively labeled thymine for one generation, radioactively labeled macromolecules will be detected in which of the following organelles? a. only in the nucleus b.only in the nucleus and mitochondria c. only in the nucleus and chloroplasts d. in the nucleus, mitochondria, and chloroplasts

d. in the nucleus, mitochondria, and chloroplasts

Researchers investigating the mechanism of vesicle transport assembled a cell-free system that included microtubules, vesicles, and ATP. However, they observed no movement of transport of vesicles because the mixture was missing which of the following components? a. Mitochondria b. contractile microfilaments c. Golgi Apparatus d. motor proteins

d. motor proteins

Cytochalasin D is a drug that prevents actin polymerization. Which of the following processes will be unaffected in cells treated with cytochalasin D? a. cytoplasmic streaming b. contraction of muscle fibers c. extension of pseudopodia d. movement of transport vesicles in the cytosol

d. movement of transport vesicles in the cytosol

Which cell would be best for studying lysosomes? a. muscle cell b. nerve cell c. bacterial cell d. phagocytic white blood cell

d. phagocytic white blood cell

If homogenized cells are fractionated by differential centrifugation, which of the following organelles will require the greatest centrifugation speed to form a pellet at the bottom of the tube? a. nuclei b. mitochondria c. chloroplasts d. ribosomes

d. ribosomes

Passive leakage of partially digested material from the small intestine into the human abdominal cavity may result from defects in which of the following type of intercellular junction? a. desmosomes b. gap junctions c. plasmodesmata d. tight junctions

d. tight junctions

Which of the following is the most appropriate technique for observing and measuring the size of ribosomes in a eukaryotic cell? a. a using a magnifying glass b. standard light microscopy c. scanning electron microscopy d. transmission electron microscopy

d. transmission electron microscopy

While abundant quantities of proteins are produced by free ribosomes in the cytosol, new proteins are also produced by which of the following organelles? a. lysosomes b.the Golgi apparatus c. the nucleolus d.mitochondria

d.mitochondria

A cell with a predominance of smooth endoplasmic reticulum is most likely specialized to carry out which of the following processes? a. storage of large quantities of water b.import and export large quantities of protein c. active secretion of large quantities of protein d.synthesis of large quantities of lipids

d.synthesis of large quantities of lipids

Which of the following statements describes a primary function of the middle lamella associated with plant cells? a. It glues adjacent cells together. b. It prevents dehydration of adjacent cells. c. It forms connections between the cytoplasm of adjacent cells. d.It prevents uptake of excess water by plant cells.

a. It glues adjacent cells together.

Which of the following statements best describes the function of the nuclear pore complex found in eukaryotic cells? a. It regulates the movement of proteins and RNAs into and out of the nucleus. b. It synthesizes the proteins required to copy DNA and make mRNA. c.It synthesizes secreted proteins. d. it assembles ribosomes from raw materials that are synthesized in the nucleus

a. It regulates the movement of proteins and RNAs into and out of the nucleus.

An organelle in a newly discovered cell contains thylakoids, DNA, and ribosomes. These findings suggest that this organelle is most likely similar to which of the following organelles? a. chloroplasts b.mitochondria c.lysosomes d.nuclei

a. chloroplasts

Tay-Sachs disease is a human genetic disorder that results in cellular accumulation of very large, complex, undigested lipids. Which of the following organelles is most likely defective in Tay-Sachs disease? a. the lysosome b.the Golgi apparatus c.the smooth endoplasmic reticulum d. the rough endoplasmic reticulum

a. the lysosome

Which of the following molecules is required by cells to assemble cilia or flagella? a. tubulin b. laminin c. actin d.intermediate filaments

a. tubulin

Cyanide binds with at least one protein complex involved in producing ATP. If a cell is exposed to cyanide, most of the bound cyanide is likely to be localized within which of the following organelles? a.mitochondria b.peroxisomes c. lysosomes d.smooth endoplasmic reticulum

a.mitochondria

If model cells have shapes that approximate rectangular solids, which of the following dimensions will provide the cell with the greatest ratio of surface area to volume (all units are in micrometers, μm)? a. 202020 b. 101010 c.101020 d.102020

b. 101010

Which of the following organelles often occupy the majority of the volume of a plant cell? a. lysosome b. central vacuole c. Golgi apparatus d. chloroplast

b. central vacuole

Examination of a cell by transmission electron microscopy reveals a high density of ribosomes in the cytoplasm. This observation suggests that the cell is actively producing large amounts of which of the following molecules? a. polysaccharides b. proteins c. lipids d.nucleic acids

b. proteins

Which of the following statements best describes one major difference between prokaryotic cells and eukaryotic cells? a. Prokaryotic cells have cell walls, while eukaryotic cells do not. b. Eukaryotic cells have flagella, while prokaryotic cells do not. c. Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not. d. Prokaryotic cells are generally larger than eukaryotic cells.

c. Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not.

Which of the following organelles is primarily responsible for the production and modification of polysaccharides that will be secreted? a. lysosome b. mitochondrion c. Golgi Apparatus d. peroxisome

c. Golgi Apparatus

An early step in the evolution of eukaryotic cells most likely involved which of the following events? a. endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell-the endosymbiont evolved into chloroplasts b. endosymbiosis of a photosynthetic archaeal cell in a larger bacterial host cell to escape toxic oxygen-the anaerobic archaea evolved into chloroplasts c. endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell-the endosymbiont evolved into mitochondria d. evolution of an endomembrane system and subsequent evolution of mitochondria from a portion of the smooth endoplasmic reticulum

c. endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell-the endosymbiont evolved into mitochondria

The nuclear lamina is an array of intermediate filaments that line the inner surface of the nuclear membrane. Disassembly of the lamina by chemical treatment would most likely result in which of the following consequences? a. closing of nuclear pores b. the inability of the nucleus to divide during cell division c. a loss of genetic information from chromosomes d. a change in the shape of the nucleus

d. a change in the shape of the nucleus

Asbestos is a material that was extensively used in construction for decades. One risk from working in a building that contains asbestos is the development of asbestosis caused by the inhalation of asbestos fibers. Cells will take up asbestos by phagocytosis, but are not able to degrade it. Toxicity most likely results from accumulation of asbestos in which of the following organelles? a. the Golgi apparatus b.nuclei c.peroxisomes d. lysosomes

d. lysosomes

A newly discovered unicellular organism isolated from acidic mine drainage is found to contain a cell wall, a plasma membrane, two flagella, and peroxisomes. Based on this information only, the organism is most likely to be ________. a. a nonmotile prokaryote b. a motile bacteriuma c. motile archaeaa d. nonmotile eukaryote f. a motile eukaryote

f. a motile eukaryote