CELL BIO

Which of the following list of terms is ordered from smallest to largest: A) Antibody, Corona Virus, Nucleus, Stu Feinstein B) Mitochondria, Kinesin, Kinetochore, Nuclear pore, Nuclear war C) Centromere, Centrosome, Centriole, Century City D) Chromophore, Chromosome, Ribosome, Rome E) Peroxisome, Chromosome, Nucleosome, Nucleus

A) Antibody, Corona Virus, Nucleus, Stu Feinstein

Connexin protein is located in: A) Gap Junctions B) Desmosome C) Centrosome D) Chromatin E) Centromere

A) Gap Junctions

Which one of the following is the correct order of phases of mitosis? A) Prophase, Prometaphase, Metaphase, Anaphase, Telophase, Cytokinesis B) Mitosis, G1, G2, S C) Condensation of Chromosomes, Pairing of homologous chromosomes, Crossing Over, Metaphase 2 D) A and C, above.

A) Prophase, Prometaphase, Metaphase, Anaphase, Telophase, Cytokinesis

Which of the following is true about the mechanisms of membrane transport? A) Simple diffusion requires cellular energy. B) Active transport requires cellular energy. C) Simple diffusion requires a membrane protein and ATP. D) Facilitated diffusion does not require a membrane protein. E) All of the above are true.

B) Active transport requires cellular energy.

A mitochondrion: A) Is about the same size as a giant squid axon cell. B) Has an electron transport chain in the inner membrane that generates a proton gradient across the membrane. C) Has a voltage gated sodium channel that binds tetrototoxin. D) Is directly affected by mutations that cause Tay-Sachs Disease. E) A and B above

B) Has an electron transport chain in the inner membrane that generates a proton gradient across the membrane.

Suppose you discover that injection of an mRNA encoding a transcription factor called mussel into a toe epithelial cell results in the toe cell becoming a muscle cell. Which conclusions can be made from this information? A) Mussel regulates the expression of cMyc in the toe epithelial cell. B) Mussel is sufficient for development of a muscle cell. C) Mussel is necessary for development a muscle cell. D) A and B are correct. E) B and C are correct.

B) Mussel is sufficient for development of a muscle cell.

Suppose you spend the day at the beach, and your skin cells are exposed to excessive UV light and extensive DNA damage occurs. Which of the following might be a likely consequence as a result of this? A) Insulin would accumulate in the smooth endoplasmic reticulum. B) Progression through the cell cycle might be halted due to cell cycle checkpoints. C) Apoptosis in skin cells would be prevented. D) A and B, above. E) All of the above.

B) Progression through the cell cycle might be halted due to cell cycle checkpoints.

Tubulin is located in: A) Gap Junctions B) Sperm Flagella C) Extracellular Matrix D) Desmosomes E) Smooth Endoplasmic Reticulum

B) Sperm Flagella

Which statement is TRUE about receptor-mediated endocytosis of low-density lipoprotein (LDL) particles? A) Clathrin is secreted and coats outside surface of a coated pit. B) The LDL particles bind to LDL receptors in coated pits. C) Absence of the LDL receptor causes Tay-Sachs. D) The coated vesicles need coats because the cytoplasm has a lower temperature and thus lower viscosity than the nucleus. E) All statements are false

B) The LDL particles bind to LDL receptors in coated pits.

Which of the following represents the correct sequence of the pathway for the synthesis and secretion of insulin, a protein secreted by the beta cells of the pancreas? A) Transcription of the insulin gene, translation on a cytoplasmic ribosome, proteolytic processing in the ER, passage through the Golgi apparatus, packaging in a secretory vesicle, secretion. B) Transcription of the insulin gene, translation on a rough ER ribosome, proteolytic processing in the ER, passage through the Golgi apparatus, secretion. C) Transcription of the insulin gene, translation on a cytoplasmic ribosome, proteolytic processing in the ER, passage through the Golgi apparatus, packaging into an LDL particle, secretion. D) Transcription of the insulin gene, translation on a cytoplasmic ribosome, proteolytic processing in the ER, passage through the vacuole, packaging in a secretory vesicle, secretion. E) None of the above.

B) Transcription of the insulin gene, translation on a rough ER ribosome, proteolytic processing in the ER, passage through the Golgi apparatus, secretion.

bacterial sex

pili

Proteoglycans are located in: A) Gap Junctions B) Sperm Flagella C) Extracellular Matrix D) Nuclear Lamina E) Smooth Endoplasmic Reticulum

C) Extracellular Matrix

In meiosis, when we first see chiasmata under a microscope, we know that _____. A) Mitochondrial mutations are occurring that will cause blindness B) Anaphase II of meiosis has occurred. C) Prophase I of meiosis is occurring D) Separation of homologous chromosome pairs is dysfunctional.

C) Prophase I of meiosis is occurring

How does the surface area-to-volume of a secretory vesicle in a pancreatic beta cell compare to the surface area-to-volume ratio of a basketball? A) The basketball has a higher ratio. B) The ratio is the same in both. C) The vesicle has a higher ratio. D) All of the above. E) None of the above.

C) The vesicle has a higher ratio.

Integrin receptors: A) Mediate cell adhesion and cell migration on extracellular matrix B) Link to microfiliaments in the cytoplasm C) Link microtubules to lipid rafts D) A and B, above. E) None of the Above.

D) A and B, above.

Suppose Susan from Susanville is studying how the corona virus enters a human lung cell. She discovers a novel mutant virus that binds to the cell surface but cannot enter the cell. Which of the following are reasonable hypotheses that might explain what is going on? A) The mutant virus has a mutation in the gene encoding the spike protein that prevents its proteolysis. B) The mutant virus has a mutation in the gene encoding the spike protein that knocks out its membrane fusion activity. C) The mutant virus has a mutation in the gene encoding the polymerase that replicates the viral RNA. D) A and B, above. E) A, B, and C, above.

D) A and B, above.

The chloroplast: A) Carries out light reactions to generate O2, ATP and NADPH B) Carries out dark reactions which use ATP and NADPH to convert CO2 to sugar. C) Is thought to be derived when a mitochondrion was engulfed by a larger cell during evolution D) A and B, above. E) A, B, and C, above.

D) A and B, above.

Suppose Mei from Mayberry discovers a novel enzyme that catalyzes the fragmentation of the nuclear envelope, and names it "nuclear envelopase". In which cells would expect this enzyme to be active? A) A non-dividing HELA cell. B) A non-dividing neuronal cell with a large nucleus. C) A dividing bacterial cell. D) A dividing cell in the inner cell mass of a 5 day old human blastocyst. E) C and D, above.

D) A dividing cell in the inner cell mass of a 5 day old human blastocyst.

Intermediate filaments are attached to: A) Gap Junctions B) Sperm Flagella C) Extracellular Matrix D) Desmosomes E) Smooth Endoplasmic Reticulum

D) Desmosomes

A lysosome: A) Is about the same size as a bacteria. B) Has an electron transport chain in the inner membrane that generates a proton gradient across the inner membrane. C) Has a voltage gated sodium channel that binds tetrototoxin. D) Is directly affected by mutations that cause Tay-Sachs Disease. E) A and B above.

D) Is directly affected by mutations that cause Tay-Sachs Disease.

Suppose you wish to test the hypothesis that the EGF receptor underlies the migration of fibroblast cells on the extracellular matrix protein collagen. Which of the following experimental approaches could be used to test your hypothesis? A) Use transmission electron microscopy to visualize the cell membrane to quantify migration speed. B) Add penicillin to inhibit caspase enzymes important in actin polymerization and determine the rate of migration. C) Use fluorescence microscopy to visualize actin in the leading edge of the cell. D) Knock out the gene for the EGF receptor and determine the effect on the rate of migration. E) All of the above.

D) Knock out the gene for the EGF receptor and determine the effect on the rate of migration.

Progeria results from genetic mutations that affect the: A) Gap Junctions B) Sperm Flagella C) Extracellular Matrix D) Nuclear Lamina E) Smooth Endoplasmic Reticulum

D) Nuclear Lamina

Suppose you discover a bacterium that infected students in Isla Vista during Halloween. You are awarded a $1Million dollar grant by Chancellor Yang to develop a new antibiotic small molecule drug that will only kill the bacteria, and not the host eukaryotic cells. You would try to develop an antibiotic that... A) Binds to the kinetochore and inhibits microtubule attachment. B) Prevents the movement of chromosomes on microtubules during cellular replication. C) Irreversibly binds to and inhibits the function of the proteins in the cell wall of the bacterial mitochondria. D) Specifically binds to a bacterial electron transport chain protein and prevents the formation of a proton gradient across the inner membrane. E) C and D, above.

D) Specifically binds to a bacterial electron transport chain protein and prevents the formation of a proton gradient across the inner membrane.

The cellular components responsible for movement of sister chromatids during anaphase in mitosis are most likely to be: A) Microtubules B) Microtubule motors C) Intermediate Filaments D) Cilia E) A and B, above.

E) A and B, above.

Cyclin-dependent kinases (or Cdks): A) Add phosphate from ATP onto proteins to activate or inactivate them. B) Are active at all times in the cell cycle. C) Act by removing phosphate groups from histone proteins. D) Are activated by cyclin proteins E) A and D, above.

E) A and D, above.

Which of the following is true about Downs Syndrome? A) It can result from nondisjunction during Meiosis I. B) It can result from nondisjunction during Meiosis II. C) It is associated with a higher incidence of Alzheimer's Disease. D) It can result from pili that form in the fertilized egg that allow transfer of plasmid DNA from the sperm. E) A, B, and C, above.

E) A, B, and C, above.

Suppose you are hired by a new startup that is trying to make a vaccine to the corona virus SARSCoV2, which is causing the current pandemic. Which of the following is a viable strategy: A) Inject antibodies to the spike protein. B) Inject a harmless viral vector that expresses the spike protein to raise an immune response against the virus. C) Inject mRNA encoding the spike protein so it is produced by host cells. D) Inject bleach. E) B and C, above.

E) B and C, above.

Histone protein is located in A) Histonapedial Nodule B) Histonosomal junction C) Chomosome D) Chromatin E) C and D, above.

E) C and D, above.

Suppose George from Georgetown discovers a unique case of retinoblastoma cancer, where the rod cells of the retina proliferate out of control and form a tumor. He isolates and studies the tumor cells and compares them to normal rod cells. Surprisingly he find that the retinoblastoma gene is not mutated in the tumor cells. Based on your knowledge of the cell cycle, what other gene mutations might give rise to the cancer? A) A mutation in the gene encoding a dyniein motor protein that prevents binding to microtubules. B) A mutation in the gene encoding cohesion that prevents separation of sister chromatids during mitosis. C) A mutation in the G1-S cyclin that prevents phosphorylation of the G1-S cyclin by the retinoblastoma protein D) A mutation in the voltage gated sodium channel that results in the channel being open all the time. E) None of the above could lead to cancer.

E) None of the above could lead to cancer.

Cells are very good at recycling. Which statement below concerning the cell's ability to recycle is correct? A) The lysosome has an inner matrix of lamins that are recycled to make pili. B) The lysosome contains hexosaminidase that breaks down proteins and provide amino acids for the synthesis of new proteins. C) The lysosome fuses with the nuclear envelope to break down sugar polymers found on proteoglycans. D) Hexose aminidase in the lysosome breaks down cholesterol stored in the nuclear envelope. E) None of the above.

E) None of the above.

The Sperm cell: A) Swims via the use of cilia. B) Donates its mitochondria to the fertilized egg. C) Has an inner and outer plasma membrane. D) All of the above. E) None of the above.

E) None of the above.

Which of the following is true? A) The fertilized egg is multipotent. B) The fertilized egg is megapotent. C) The fertilized egg is impotent. D) The fertilized egg is totipluripotent. E) None of the above.

E) None of the above.

Which of the following structure-function pairs is correct? A) Nuclear pores - defective function leads to Progeria. B) Active Transport - ethanol movement across the membrane C) Peptidoglycan - chloroplast cell wall D) Proteoglycan - mostly protein with small amounts of sugar E) Nucleolus - where the biogenesis of ribosomes occurs.

E) Nucleolus - where the biogenesis of ribosomes occurs.

The enzyme Cytochrome P450 is located in: A) Tight junctions B) Sperm mitochondria C) Cytoplasm D) Desmosomes E) Smooth endoplasmic reticulum

E) Smooth endoplasmic reticulum

Kidney filter

Extracellular Matrix

Kinesin

Extracellular Matrix and Motor protein

A mitochondrion: a.Is about the same size as a giant squid axon cell. b.Has an electron transport chain in the inner membrane that generates a proton gradient across the membrane. c.Has a voltage gated sodium channel that binds tetrototoxin. d.Is directly affected by mutations that cause Tay-Sachs Disease. e.A and B above

Has an electron transport chain in the inner membrane that generates a proton gradient across the membrane.

cervical cancer

Henrietta Lack

Tay Sachs Disease

Lysosome

Microtubules

Mitotic Spindle

Which of the following statements regarding the cytoskeleton of eukaryotic cells is true? a. Amoeboidal movement requires the ATP-dependent polymerization of actin into microfilaments b. A silent mutation causes an improper splicing event of alpha tubulin in patients with progeria c. Amoeboidal movement requires the ATP-dependent polymerization of tubulins into microtubules d. Both micro- and intermediate filaments are associated with motor proteins that move cargo in the cell e. Actin polymerization is directed by Microfilament Organizing centers (MTOCs)

a. Amoeboidal movement requires the ATP-dependent polymerization of actin into microfilaments

Consider the graph below to answer the following question. Sample II was derived from a cell that was in G2 of Interphase. At the end of mitosis, an individual daughter cell will have DNA content comparable to a. Sample I b. Sample II c. Sample III d. Halfway between sample I and II e. None of the above.

a. Sample I

Promising potential treatments being tested for the treat Alzheimer's disease include: Mark All that Apply a. microtubule stabilizers b. antibodies that bind and scavenge A?8? c. CAR-T cells d. Penicillin e. Feinsteinesterase

a. microtubule stabilizers b. antibodies that bind and scavenge A?8?

Suppose you are a doctor treating a patient with hypercholesterolemia. Surprisingly, you do not find any mutations in the LDL receptor gene that would explain the disease. Which of the following genes might contain mutations that could potentially give rise to the disease? a. the gene encoding clathrin b. a gene encoding enzymes in the Calvin cycle (dark reactions) c. a gene encoding an enzyme in the pathway that makes suberin d. all of the above e. none of the above

a. the gene encoding clathrin

Which statement is TRUE about receptor-mediated endocytosis of low density lipoprotein (LDL) particles? a.Clathrin coats the internal (inside the cell) surface of a coated pit. b.The LDL particles bind to LDL receptors in the nucleus c.Absence of the LDL receptor causes progeria. d.The coated vesicles need coats because the cytoplasm has a lower temperature and thus lower viscosity than the nucleus. e.All statements are true (i.e. none are false)

a.Clathrin coats the internal (inside the cell) surface of a coated pit.

The Electron Transport Chain: a.Is localized to the inner membrane of the mitochondrion b.Is localized to the outer membrane of the chloroplast c.Was localized to outer membrane of proteobacteria that were engulfed by a larger cell during evolution d.A and B e.A, B and C

a.Is localized to the inner membrane of the mitochondrion

Which of the following list of terms is ordered from smallest to largest: a.Lysosome, Mitochondrion, Nucleus, Whale b.Nucleus, Kinesin, Nuclear pore, Nuclear war c.Centrosome, Centriole, Century City d.Peroxisome, Ribosome, Dynein e.Peroxisome, Chromosome, Nucleosome, Nucleus

a.Lysosome, Mitochondrion, Nucleus, Whale

Which of the following is a possible mechanism of action of an antibiotic against the bacterium E. coli? a. Inhibition of the binding site of importins in the nuclear pores b. Inhibition of the synthesis of the E. coli cell wall c. Inhibition of the ATP synthase in the mitochondria d. Inhibition of the signal peptides required to target proteins to the endomembrane system e. All the above can potentially kill E. coli

b. Inhibition of the synthesis of the E. coli cell wall

Suppose Mark in Markleeville discovers that a loss of function mutation in a gene encoding a transcription factor called PPC results in the loss of beta cells in the pancreas. Which conclusions can be made from this information? a.PPC regulates the expression of insulin in beta cells b.PPC is necessary for development of the beta cells c.PPC is sufficient for development of the beta cells d.A and C are correct e.B and C are correct

b.PPC is necessary for development of the beta cells

Suppose you are studying a new type of brain cancer, where the neuronal cells in the brain proliferate out of control and form a tumor. You obtain a sample of the tumor and study the tumor cells in the lab. You hypothesize that a gene important in the cell cycle is mutated. Which of the following are likely candidates that would explain the uncontrolled proliferation of these cells? a. A mutation in the gene encoding an astral microtubule protein that prevents the proper formation of the metaphase plate. b. A mutation in the gene encoding cohesin that prevents separation of sister chromatids during mitosis. c. A mutation in the S cyclin that prevents it from acting in the S phase checkpoint. d. A mutation in the voltage gated sodium channel that results in the channel being open all the time, leading to unrestrained cell growth. e. All of the above could lead to cancer.

c. A mutation in the S cyclin that prevents it from acting in the S phase checkpoint.

Suppose you wish to develop a drug to fight cancer. Which of the strategies below would be the best approach? Mark all that apply. a. Develop an inhibitor of the dynamic instability of actin microfilaments. b. Develop a drug that blocks the association of the origin of replication with the plasma membrane to halt DNA synthesis. c. Develop an inhibitor of the dynamic instability of microtubules. d. Genetically modify T cells to attack the tumor. e. Knock out the tumor cell gene encoding the G1/S cyclin.

c. Develop an inhibitor of the dynamic instability of microtubules. d. Genetically modify T cells to attack the tumor. e. Knock out the tumor cell gene encoding the G1/S cyclin.

The evolution of eukaryotic cells most likely involved ________. a. endosymbiosis of an oxygen-using bacterium in a larger cell - the endosymbiont evolved into chloroplasts b. endosymbiosis of a photosynthetic archaeal cell in a larger cell to escape toxic oxygen - the anaerobic archaea evolved into chloroplasts c. endosymbiosis of an oxygen-using bacterium in a larger 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 e. engulfment of a proteobacterium by a larger cell - the proteobacterium becomes a chloroplast

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

Which of the following can enter a human neuron via passive diffusion? a. LDL b. Na+ c. ethanol d. water e. neurotransmitter

c. ethanol

Suppose a young boy suffering from a metabolic disease is always tired and fatigued, and shows defects in vision. Which of the following organelles is most likely malfunctioning in this disease? a. lysosomes b. Golgi apparatus c. mitochondria d. smooth endoplasmic reticulum e. rough endoplasmic reticulum

c. mitochondria

Which of the following represents the correct sequence of the pathway for the synthesis and secretion of insulin, a protein secreted by the beta cells of the pancreas? a. transcription of the insulin gene, translation on a cytoplasmic ribosome, proteolytic processing in the ER, passage through the Golgi apparatus, packaging in a secretory vesicle, secretion. b. transcription of the insulin gene, translation on a rough ER ribosome, proteolytic processing in the ER, passage through the Golgi apparatus, packaging in a lysosome, secretion. c. transcription of the insulin gene, translation on a rough ER ribosome, proteolytic processing in the ER, passage through the Golgi apparatus, packaging in a secretory vesicle, fusion of the secretory vesicle to the plasma membrane. d. transcription of the insulin gene, translation on a cytoplasmic ribosome, proteolytic processing in the ER, passage through the vacuole, packaging in a secretory vesicle, secretion. e. transcription of the insulin gene, translation on a cytoplasmic ribosome, proteolytic processing in the ER, passage through the Golgi apparatus, packaging into an LDL particle, secretion.

c. transcription of the insulin gene, translation on a rough ER ribosome, proteolytic processing in the ER, passage through the Golgi apparatus, packaging in a secretory vesicle, fusion of the secretory vesicle to the plasma membrane.

How does the surface area-to-volume of a secretory vesicle in a pancreatic beta cell compare to the surface area-to-volume ratio of a frog egg? a.The frog egg has a higher ratio b.The ratio is the same in both c.The secretory vesicle has a higher ratio d.None of the above

c.The secretory vesicle has a higher ratio

Centrosome

centriole

Calcium 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 e. calcium pieholes

d. gap junctions

Where are proteins produced other than on ribosomes free in the cytosol or ribosomes attached to the endoplasmic reticulum? a. in lysosomes b. in the Golgi apparatus c. in the nucleolus d. in mitochondria e. C and D

d. in mitochondria

Which one of the following statements is TRUE? a. The larger the cell, the larger the surface area to volume ratio. b. Cells need to be large enough to allow small molecules to diffuse from the surface to deep within the cytoplasm more slowly. c. Prokaryotic cells need to be limited in size to allow them to pass through the plasma membrane and become endosymbionts to eukaryotes. d. The smaller the cell, the larger the surface area to volume ratio. e. B and D

d. The smaller the cell, the larger the surface area to volume ratio.

Chloroplast

d. Thylakoid

The nuclear lamina is an array of intermediate filaments that line the inner side of the nuclear membrane. If a chemical treatment caused the lamina to disassemble, what would you expect to be the most likely immediate consequence? 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 e. Tay-Sachs disease

d. a change in the shape of the nucleus

Asbestos is a material that was once used extensively in construction, including in the Bio 2 building. 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. As a result, asbestos fibers accumulate in ________. a. the Golgi apparatus b. nuclei c. peroxisomes d. lysosomes e. asbestosomes

d. lysosomes

A lysosome: a.Is about the same size as a bacterium. b.Has an electron transport chain in the inner membrane that generates a proton gradient across the inner membrane. c.Has a voltage gated sodium channel that binds tetrototoxin. d.Is directly affected by mutations that cause Tay-Sachs Disease. e.A and B above

d.Is directly affected by mutations that cause Tay-Sachs Disease.

Progeria results from genetic mutations that affect the: a.Gap Junctions b.Sperm Flagella c.Extracellular Matrix d.Nuclear Lamina e.Smooth Endoplasmic Reticulum

d.Nuclear Lamina

Suppose a Patty on the Patio discovers a novel pathogenic bacteria that is spreading all over the world. If you were to develop a new antibiotic small molecule drug, what cellular structure/protein(s) could you target that would only kill the bacteria, and not the host eukaryotic cells? An antibiotic that... a.Binds to the nuclear envelope b.Prevents the multiplication of mitochondria by inhibiting their division c.Irreversibly binds to and inhibits the function of the proteins in the cell wall of the bacterial mitochondria d.Targets and inhibits synthesis of the cell wall component, peptidoglycan e.C and D, above

d.Targets and inhibits synthesis of the cell wall component, peptidoglycan

Nucleosomes contain: a. positively charged histones b. negatively charged DNA c. ribosomes d. mitochondria e. A and B above

e. A and B above

Suppose you are investigating the brain of a deceased Alzheimer's patient. You prepare tissue slices and examine them using a fluorescence microscope. Which of the following might you expect to see: a. neurofibrillary tangles that stain positive for the protein tau b. enlarged lysosomes that stain positive for cellulose c. amyloid plaques that stain positive for the protein tau d. amyloid plaques that stain positive for the protein A?8? e. A and D

e. A and D

The human genome contains: a. About 19,000 genes b. 3.2 billion basepairs c. About 31,00 genes d. DNA e. A, B and D

e. A, B and D

Which of the following statements best characterizes fluorescence microscopy. a. fluorescent dyes coupled to antibodies are used in combination with a scanning confocal electron microscope. b. fluorescent dyes coupled to antibodies are used to determine protein localization in a cell using light microscopy. c. primary antibodies bound to antigens are detected by secondary antibodies tagged with a fluorescent dye. d. fluorescence microscopy yields 0.2 nanometer high resolution images of individual molecules. e. B and C

e. B and C

Suppose you wish to test the hypothesis that actin treadmilling underlies the migration of HeLa cells on an extracellular matrix that allows an intermediate amount of adhesion. Which of the following experimental approaches could be used to test your hypothesis? a. Add a statin to inhibit the biosynthesis of cholesterol to deplete actin-containing lipid rafts and determine the rate of migration. b. Add penicillin to inhibit transpeptidase to prevent the actin treadmilling in peptidoglycan-containing microfilaments and determine the rate of migration. c. Use fluorescence microscopy to visualize actin in the leading edge of the cell. d. Add an inhibitor of integrin receptors that link to actin filaments in desmosomes and determine the rate of migration. e. Inject a compound that stabilizes actin microfilaments to prevent depolymerization at the minus end and determine the effect on the rate of migration.

e. Inject a compound that stabilizes actin microfilaments to prevent depolymerization at the minus end and determine the effect on the rate of migration.

Which of the following events increase genetic diversity in meiosis? a. random distribution of the two homologs of a pair to the daughter cells during meiosis I random assortment during meiosis II b. crossing over between homologs during prophase of meiosis I c. random assortment during meiosis II d. retinoblastoma protein phosphorylation e. More than one of the above increases genetic diversity

e. More than one of the above increases genetic diversity

A newly discovered unicellular organism isolated from acidic mine drainage is found to contain a cell wall, a plasma membrane, two flagella, and mitochondria. Based just on this information, the organism is most likely ________. a. a nonmotile prokaryote b. a motile bacterium c. a motile archaea d. a nonmotile eukaryote e. a motile eukaryote

e. a motile eukaryote

Which of the following is an organelle that is surrounded by only a single phospholipid bilayer? a. chloroplast b. ribosome c. nucleus d. mitochondria e. none of the above

e. none of the above

Most people think that recycling is good for the environment. Which statement below concerning the cell's ability to recycle is correct? a.The lysosome has an inner matrix of lamins that are recycled to make pili. b.The lysosome contains hexosaminidase that breaks down proteins and provide amino acids for the synthesis of new proteins. c.The lysosome fuses with the nuclear envelope to break down sugar polymers found on proteoglycans. d.Hexose aminidase in the lysosome breaks down cholesterol stored in the nuclear envelope. e.None of the above.

e.None of the above.

Intermediate filaments

human hair