MCB 2010: Ch 3

true

Mitochondria and chloroplasts are thought to have once been free-living bacteria that invaded another cell. ⊚ true ⊚ false

C) transport proteins.

Most solutes pass through the cytoplasmic membrane via A) osmosis. B) diffusion. C) transport proteins. D) secretion. E) aquaporins.

E) is by means of flagella AND may be referred to as run and tumble.

Movement in bacteria A) is directly to or away from a stimulus. B) relies on the beating of cilia. C) is often referred to as run and tumble. D) may involve pili AND may be referred to as twist and turn. E) is by means of flagella AND may be referred to as run and tumble.

false

Penicillin affects the synthesis of phospholipids, thereby producing weak membranes and lysis of the bacteria. ⊚ true ⊚ false

C) actively growing bacteria AND Gram-positive bacteria.

Penicillin would be most effective against A) actively non-growing bacteria AND Gram-positive bacteria. B) non-growing bacteria AND Gram-negative bacteria. C) actively growing bacteria AND Gram-positive bacteria. D) actively growing bacteria AND Gram-negative bacteria. E) any actively growing bacteria.

E) Peptidoglycan and outer membrane - B

Consider the Venn diagram pertaining to the bacterial cell wall and select the INCORRECT characterization.Remember that characteristics shared by two or more items are found in the circle overlaps. A) Stains with simple stain - B B) Lipid A and O antigen - C C) Peptidoglycan and teichoic acids - A D) Protein and carbohydrate - B E) Peptidoglycan and outer membrane - B

C) Mitochondria, nucleus, unicellular - F

Consider the Venn diagram pertaining to the three domains and select the INCORRECT characterization.Remember that characteristics shared by two or more items are found in the circle overlaps. A) Mitochondria, 80S ribosomes, cell wall - G B) Peptidoglycan, 70S ribosomes, diplococcus - A C) Mitochondria, nucleus, unicellular - F D) Unicellular, ribosomes, DNA - E E) Prokaryote, 70S ribosomes, DNA - B

E) magnification is higher.

Electron microscopes differ from light microscopes in that A) light replaces electrons. B) glass lenses replace electromagnetic lenses. C) resolution is lower. D) magnification is lower. E) magnification is higher.

A) a dormant cell type

Endospores are A) a dormant cell type. B) involved in bacterial reproduction. C) obligate intracellular parasites. D) sensitive to heat and dessication. E) made by all bacterial genera.

false

Endospores are involved in bacterial reproduction. ⊚ true ⊚ false

A) consists of lipopolysaccharide.

Endotoxin A) consists of lipopolysaccharide. B) determines bacterial shape. C) may have different effects depending on thebacterial species. D) is toxic due to the effects of the peptide side chains. E) is found in Gram-positive cells.

A) mitochondria AND plasmids

Extrachromasomal DNA is found in ______. A) mitochondria AND plasmids B) mitochondria only C) plasmids only D) the nucleoid AND nucleolus E) mitochondria AND nucleus

A) both transport molecules into or out of a cell.

Facilitated diffusion and active transport A) both transport molecules into or out of a cell. B) are both not very specific as to which molecules are transported. C) both require a concentration gradient to function. D) both require use of energy in order to transport the molecules. E) both only transport molecules into a cell.

A) Streptococcus pyogenes, a Gram-positive bacterium that can cause strep throat.

Given what you know about the bacterial cell wall, infections caused by which of the following would theoretically respond best to treatment with penicillin? A) Streptococcus pyogenes, a Gram-positive bacterium that can cause strep throat. B) Escherichia coli, aGram-negative bacterium that can cause urinary tract infections. C) Vibrio cholerae, a Gram-negative organism that causes serious diarrhea. D) Mycoplasma pneumoniae,a pleomorphic bacterium that causes pneumonia. E) Candida albicans, a yeast that can cause diaper rash in infants.

E) The proton motive force involves moving electrons from one side of the nuclear membrane to the other.

Select the FALSE statement regarding the proton motor force. A) The proton motive force is set up when protons are moved out of the cell by the electron transport chain. B) The energy of the proton motive force is harvested by mechanisms that allow protons to move back into the cell. C) The energy of the proton motive force is used to drive certain cellular processes, including ATP synthesis. D) The energy of the proton motive force is used to power certain transport systems and some forms of motility. E) The proton motive force involves moving electrons from one side of the nuclear membrane to the other.

E) The proton motive force involves a pH gradient component AND the proton motive force can be used for active transport processes.

Select the TRUE statement(s) about the proton motive force. A) The proton motive force always involves the inner mitochondrial membrane. B) The proton motive force involves a pH gradient component. C) The proton motive force can be used for active transport processes. D) The proton motive force involves movement of hydrogen ions across the nuclear membrane by the electron transport chain. E) The proton motive force involves a pH gradient component AND the proton motive force can be used for active transport processes.

false

Smooth endoplasmic reticulum is involved in protein synthesis. ⊚ true ⊚ false

C) atomic force microscope.

Specimens can be observed at the atomic level using a(n) A) scanning electron microscope. B) transmission electron microscope. C) atomic force microscope. D) fluorescence microscope. E) light microscope.

B) crystal violet, iodine, alcohol, safranin.

The CORRECT order of reagent use in the Gram stain reaction is A) safranin, alcohol, methylene blue, iodine. B) crystal violet, iodine, alcohol, safranin. C) methylene blue, alcohol, safranin, iodine. D) crystal violet, alcohol, iodine, safranin. E) alcohol, safranin, iodine, crystal violet

C) safranin.

The Gram stain and the endospore stain both use A) crystal violet. B) iodine. C) safranin. D) malachite green. E) acidic dyes.

C) may be used for protection AND may be used to help the bacteria adhere to surfaces.

The capsule A) may be used for protection AND may be involved in movement. B) may be used to help the bacteria adhere to surfaces AND may be involved in movement. C) may be used for protection AND may be used to help the bacteria adhere to surfaces. D) may be involved in movement AND may be involved in energy production. E) may be involved in energy production AND may be used for protection.

C) has a thin peptidoglycan layer AND is characterized by an outer membrane containing LPS.

The cell wall of Gram-negative organisms A) has a thick peptidoglycan layer ANDis characterized by an outer membrane containing LPS. B) has a thick peptidoglycan layer. C) has a thin peptidoglycan layer AND is characterized by an outer membrane containing LPS. D) has a thin peptidoglycan layer. E) is more permeable to various molecules than the Gram-positive cell wall.

B) contains a thick layer of peptidoglycan.

The cell wall of Gram-positive bacteria A) contains a thin layer of peptidoglycan. B) contains a thick layer of peptidoglycan. C) is an excellent barrier to most molecules. D) contains an outer membrane containing LPS. E) contains a thick layer of peptidoglycose.

C) regulate movement of molecules that enter and leave the cell.

The cytoplasmic membrane of both eukaryotes and prokaryotes functions to A) form rough and smooth endoplasmic reticulum. B) produce energy in the form of ATP. C) regulate movement of molecules that enter and leave the cell. D) form lysosomes, peroxisomes, and Golgi apparatus. E) produce peptidoglycanor chitin cell walls.

E) is applicable to only a few groups of bacteria.

The endospore stain A) is applicable to many groups of bacteria. B) usually shows the spores as pink structures among a background of blue cells. C) uses crystal violet as the primary stain. D) is an example of a negative stain. E) is applicable to only a few groups of bacteria.

A) is a dynamic structure composed of microtubules, microfilaments, and intermediate filaments.

The eukaryotic cell cytoskeleton A) is a dynamic structure composed of microtubules, microfilaments, and intermediate filaments. B) is a static structure that gives a rigid, defined shape to the cell. C) consists of flagella, filaments and cilia that have been internalized. D) has no known function in an animal cell. E) is a dynamic structure composed of nucleic acids, phospholipids, and proteins.

C) peptidoglycan.

The macromolecule found in the cell walls of all bacteria is A) lipid A. B) teichoic acid. C) peptidoglycan. D) glycocalyx. E) chitin.

A) cell wall structure.

The major criterion used in placing bacteria into different groups is based on differences in A) cell wall structure. B) cell membrane permeability. C) presence or absence of flagella. D) detergent susceptibility. E) presence or absence of cytoplasmic membrane.

B) contain sterols for strength.

The membranes of eukaryotes and Mycoplasma A) contain peptidoglycan. B) contain sterols for strength. C) contain ergosterol. D) are fixed static structures. E) are phospholipid unilayers.

B) differential interference contrast microscope.

The microscope that allows the specimen to appear three-dimensional is the A) phase contrast microscope. B) differential interference contrast microscope. C) fluorescence microscope. D) transmission electron microscope. E) compound microscope.

C) is a double membrane sac containing DNA and is found in eukaryotes.

The nucleus A) is a single phospholipid membrane sac containing prokaryotic DNA. B) is a smaller structure contained within the eukaryotic nucleolus. C) is a double membrane sac containing DNA and is found in eukaryotes. D) cannot transport molecules to the cytoplasm due to the double membrane barrier. E) is a triple phospholipid membrane sac containing prokaryotic RNA.

B) transport proteins, permeases, AND carriers.

The proteins of bacteria that are involved in the movement of small molecules into the cell are called A) transport proteins, carriers, AND peptidases. B) transport proteins, permeases, AND carriers. C) permeases, carriers, AND peptidases. D) carriers, peptidases, AND porases. E) peptidases, porases, AND permeases.

A) separate clearly two objects that are very close together.

The resolving power of a microscope is described as the ability of the microscope to A) separate clearly two objects that are very close together. B) magnify an object and its surroundings. C) separate the colors of an organism's internal structure. D) magnify structures at various depths in a tissue. E) combine the images of two objects that are very close together.

B) flagella.

The structures used for motility in both eukaryotes and prokaryotes are A) cilia. B) flagella. C) pili. D) fimbriae. E) microvilli.

C) ocular and objective.

The two magnifying lenses found in a light microscope are the A) basic and transverse. B) small and large. C) ocular and objective. D) simple and phase. E) ocular and phase.

C) resolution.

The use of oil with certain high-power objective lenses increases A) magnification. B) reflection. C) resolution. D) contrast. E) color.

A) It is the ingestion of particles and may be performed by animal cells.

Which is the CORRECT definition of phagocytosis? A) It is the ingestion of particles and may be performed by animal cells. B) It is the ingestion of particles and may be performed by bacteria. C) It is the secretion of proteins from a bacterium into the environment. D) It is the formation of a lysosome filled with peroxidases. E) It is the uptake of particles across the animal cell wall.

E) All of the answer choices are true.

Which is/are TRUE regarding the cell wall of bacteria? A) It determines the shape of the bacteria. B) It prevents the bacteria from bursting. C) It contains peptidoglycan. D) It may be targeted by antimicrobials. E) All of the answer choices are true.

C) Decolorizing for too long AND using old bacterial cultures.

Which may result in Gram-positive bacteria appearing to be Gram-negative? A) Decolorizing for too long AND using young bacterial cultures. B) Not decolorizingfor long enough AND using young bacterial cultures. C) Decolorizing for too long AND using old bacterial cultures. D) Not decolorizing for long enough AND using old bacterial cultures. E) Forgetting to decolorize AND using old bacterial cultures.

B) Scanning electron microscope

Which microscope would be the BEST selection for examination of a virus? A) Confocal scanninglaser microscope B) Scanning electron microscope C) Dark-field lightmicroscope D) Atomic force microscope E) Compound light microscope

E) Lipopolysaccharide

Which molecule(s) is (are) NOT associated with the cell wall of Gram-positive bacteria? A) Peptidoglycan B) D-form amino acids C) Teichoic acids D) Peptidoglycan, D-form amino acids, AND teichoic acids E) Lipopolysaccharide

C) Mycoplasma pneumoniae

Which of the following bacteria lack(s) a peptidoglycan cell wall? A) Treponema pallidum B) Mycobacterium tuberculosis C) Mycoplasma pneumoniae D) Staphylococcus aureus E) These all contain a cell wall—they are bacteria.

A) They are more obviously compartmentalized than prokaryotes.

Which of the following is TRUE regarding eukaryotic cells? A) They are more obviously compartmentalized than prokaryotes. B) They usually have a single circular supercoiled piece of DNA. C) They contain peptidoglycan in the cell wall. D) They have the same size ribosomes as prokaryotes. E) They all produce endospores in adverse conditions.

B) Water

Which of the following is most abundant in bacterial cells? A) Glucose B) Water C) Peptidoglycan D) Phospholipid E) Glycoprotein

C) Bright-field

Which of the following microscope types would be LEAST useful in viewing unstained living cells? A) Phase contrast B) Differential interference contrast C) Bright-field D) Dark-field E) Fluorescence

C) Acid-fast stain AND Gram stain.

Which of the following stains are considered differential? A) Capsule stain AND Gram stain. B) Flagella stain AND acid-fast stain. C) Acid-fast stain AND Gram stain. D) Acid-fast stain AND capsule stain. E) Gram stain AND flagellastain.

A) Bacteria move by means of flagella, while archaea move by means of archaella.

Which of the following statements about flagella, pili and archaella is CORRECT? A) Bacteria move by means of flagella, while archaea move by means of archaella. B) Archaella and flagella are identical in structure and are used for attachment. C) Flagella are unique to bacteria; no other cell type has them. D) Sex pili are used for slow, gliding motion in archaea. E) Pili and fimbriae are both types of flagella used for movement.

C) It may be digested by lysozyme.

Which of the following statements regarding peptidoglycan is TRUE? A) It may be digested by penicillin. B) It consists of a long string of NAG coupled to a long string of NAM. C) It may be digested by lysozyme. D) It is found in bacteria, archaea, and plants. E) It is only found in Gram-positive cells.

C) It uses the dyes methylene blue and safranin.

Which of the statements about immunofluorescence is FALSE? A) It uses fluorescently tagged molecules. B) It makes use ofthe specificity in binding of antibodies. C) It uses the dyes methylene blue and safranin. D) It would require a special UV microscope. E) Stained cells often appear bright yellow-green against a black background.

A) brown; purple

A modified Gram-stain procedure uses Bismark brown as a counterstain instead of safranin. In this case, Gram-negative cells would appear _____, while Gram-positive cells would appear _____. A) brown; purple B) purple; purple C) pink; purple D) colorless; brown E) brown; colorless

A) Potentially yes—it could be used against some bacteria, but wouldn't be effective for those that don't use a flagellum to move around.

A new drug is developed that inhibits formation of flagellafilament by impairing production of the protein flagellin. Is this going to be an effective medication? A) Potentially yes—it could be used against some bacteria, but wouldn't be effective for those that don't use a flagellum to move around. B) Potentially yes, but only if it could be shown that the drug also didn't impair the production of the eukaryotic flagellum. C) Not at all—our eukaryotic cells depend on flagella to move around in our body, and this drug would impair that function. D) Not at all—bacterial flagella are produced using microtubules, not the protein flagellin. This drug would be useless in eliminating bacteria. E) Not at all—this medication would affect cells like the ciliated respiratory epithelial cells, and would cause potentially fatal side-effects.

C) we should next proceed by repeating the experiment in test tubes using intact Gramnegative cells to see if the drug binds with the same strength.

A new medication is developed that targets and binds to the lipid A portion of LPS in Gram-negative bacterial cells. This drug shows a high degree of binding and activity against purified lipid A in an experiment carried out in test tubes. Based on this information, A) we should fast-track this drug and get it out to physicians immediately to help prevent Gram-negative toxic/septic shock in humans. B) we should do some animal testing with intact Gram-negative cells and the medication before we jump to any conclusions. C) we should next proceed by repeating the experiment in test tubes using intact Gramnegative cells to see if the drug binds with the same strength. D) we should abandon the drug entirely. Binding to lipid A won't kill the bacteria, so the drug is useless to develop further. E) we should assume that the medication will be effective against all bacteria, including Mycoplasmas, and that it is ready for use in humans.

C) Mitochondria and chloroplasts possess 70S ribosomes. This drug might be impairing the activity of mitochondria in animal cells.

A newly developed antibiotic drug shows promise by inhibiting prokaryotic 70S ribosomes in initial studies. However, when animal studies are begun, it's noted that the drug also inhibits growth of animal cells. Select the statement that may be explain howthis can be happening. A) The function of ribosomes is identical, no matter their size, so a drug that can affect 70S ribosomes will also impair 80S ribosomes. B) Mitochondria and chloroplasts possess 70S ribosomes. This drug might be impairing the activity of chloroplasts in animal cells. C) Mitochondria and chloroplasts possess 70S ribosomes. This drug might be impairing the activity of mitochondria in animal cells. D) Prokaryote cells are identical to animal cells; a drug that impacts one will also always impact the other. E) There really is no reasonable explanation for this observation; the experiment should be repeated to get a different outcome.

D) Mycoplasma species do not have a peptidoglycan cell wall and are thus not impacted by penicillin.

A patient comes to see you, complaining of a very sore throat. When you examine her, you find that she has a fever of 39.9oC, and you observe that her throat is extremely red, with pus on her tonsils. You swab the pus and make a slide, which you then send to the clinical lab for Gram staining. The lab sends back a report in which it is noted that the slide has manylong chains of round cells that have stained purple in color. As she is preparing to leave your office, the patient mentions that her brother had pneumonia a couple of years ago and that penicillin had not helped him. You ask her if she remembers the name of the organism causing her brother's illness and she tells you it was Mycoplasmasomething or other, that she can't quite remember. You tell her that the reason penicillin did not help her brother is that A) you know her brother did not take the full course of antibiotics, so some of the Mycoplasma cells survived. B) Mycoplasma species are Gram-negative, and penicillin cannot penetrate the LPS layer of these cells, so the cells survive. C) Mycoplasma species are acid-fast bacteria, so they have mycolic acids in the cell wall that penicillin does not destroy. D) Mycoplasma species do not have a peptidoglycan cell wall and are thus not impacted by penicillin. E) Mycoplasmas are viruses and antibiotics do not work against viral infections.

B) bacterial

A patient comes to see you, complaining of a very sore throat. When you examine her, you find that she has a fever of 39.9oC, and you observe that her throat is extremely red, with pus on her tonsils. You swab the pus and make a slide, which you then send to the clinical lab for Gram staining. The lab sends back a report in which it is noted that the slide has manylong chains of round cells that have stained purple in color. Based on the Gram staining, you suspect that the patient has a _____ infection. A) fungal B) bacterial C) protozoan D) algal E) prion

C) round; thick

A patient comes to see you, complaining of a very sore throat. When you examine her, you find that she has a fever of 39.9oC, and you observe that her throat is extremely red, with pus on her tonsils. You swab the pus and make a slide, which you then send to the clinical lab for Gram staining. The lab sends back a report in which it is noted that the slide has manylong chains of round cells that have stained purple in color. You inform the patient that the results of the Gram stain indicate to you that the bacteria in her throat are ______ in shape, and have a ______ cell wall. A) round; thin B) cylindrical; thick C) round; thick D) spiral; thick E) cylindrical; thin

A) peptidoglycan

A patient comes to see you, complaining of a very sore throat. When you examine her, you find that she has a fever of 39.9oC, and you observe that her throat is extremely red, with pus on her tonsils. You swab the pus and make a slide, which you then send to the clinical lab for Gram staining. The lab sends back a report in which it is noted that the slide has manylong chains of round cells that have stained purple in color. You perform a rapid strep test on the patient, which comes up positive. You tell her that she most likely has strep throat, caused by Streptococcus pyogenes. You prescribe penicillin for her, and tell her that this antibiotic is effective because it interferes with the synthesis of ______ by the pathogen. A) peptidoglycan B) capsule material C) ribosomes D) proteins E) ATP

C) maybe, but viruses cannot be observed without an electron microscope.

A patient comes to see you, complaining of a very sore throat. When you examine her, you find that she has a fever of 39.9oC, and you observe that her throat is extremely red, with pus on her tonsils. You swab the pus and make a slide, which you then send to the clinical lab for Gram staining. The lab sends back a report in which it is noted that the slide has manylong chains of round cells that have stained purple in color. Your patient asks you whether you also observed viruses on the slide. You tell her A) yes, but they are of no concern because viruses are never pathogenic. B) maybe, but there were too few to observe among the bacteria. C) maybe, but viruses cannot be observed without an electron microscope. D) unlikely, because viruses seldom cause sore throats in people. E) no, because viruses are always Gram negative.

A) The penicillin wouldn't affect the Archaea because it targets peptidoglycan, which is not foundin their cell walls.

A research laboratory is investigating environmental factors that would inhibit the growth of Archaea. One question they have is whetheradding the antibiotic penicillin would be effective in controlling their growth. What do you think the outcome would be if they tried this? A) The penicillin wouldn't affect the Archaea because it targets peptidoglycan, which is not foundin their cell walls. B) The penicillin will inhibit peptidoglycan synthesis and thus cell wall formation in the Archaea, killing them. C) The penicillin will slow down the growth of the Archaea by damaging the cell wall, but they will be able to grow slowly. D) The penicillin willenhance the growth of the Archaea by providing a rich nutrientsource. E) The penicillin will inhibit cell division in the Archaea, forcing them to form endospores for survival.

B) would be highly toxic for human beings if taken orally, but might be useful as a topical antibiotic skin cream. The top layer of skin cells is dead anyway, so it wouldn't matter if the drugdamaged those cells.

A research laboratory is trying to produce new antibiotics. They develop a medication that detaches the hydrophilic heads from the phospholipids in cytoplasmic membranes. This drug A) would be highly toxic and completely useless for human beings and could never be used—our cells also have cytoplasmic membranes with hydrophilic head groups! B) would be highly toxic for human beings if taken orally, but might be useful as a topical antibiotic skin cream. The top layer of skin cells is dead anyway, so it wouldn't matter if the drugdamaged those cells. C) would be highly toxic only to bacteria, making it an excellent drug to develop and test further. Humans have a different phospholipid structure in their cytoplasmic membranes from bacteria. D) would generally not be toxic enough to damage Gram-negative bacteria, as their cytoplasmic membranes lie under a thick layer of peptidoglycan. However, it would be effective against Gram-positive cells. E) would not work against any bacteria, because they do not have a cytoplasmic membrane; however, it might be effective against helminths and viruses.

A) purple; purple

A student mistakenly swapped the two stains in the Gram stain, thereby using safranin as the primary stain and crystal violet as the counterstain. With this error, Gram-positive cells would appear _____, while Gram-negative cells would appear _____. A) purple; purple B) pink; pink C) purple; colorless D) pink; colorless E) colorless; colorless

B) high surface area relative to low cell volume AND more rapid growth rates.

An advantage of the smaller size of prokaryotes, compared to eukaryotes, is A) high surface area relative to low cell volume AND slower growth rates. B) high surface area relative to low cell volume AND more rapid growth rates. C) more rapid growth rates AND compartmentalization of cellular processes. D) compartmentalization of cellular processes AND low surface area relative to low cell volume. E) more rapid growth rates AND low surface area relative to high cell volume.

false

Bacillus and Clostridium are medically relevant groups of bacteria that characteristically stain acid-fast. ⊚ true ⊚ false

D) movement in response to a chemical.

Chemotaxis refers to A) movement toward light. B) movementtoward a chemical. C) movement away from a chemical. D) movement in response to a chemical. E) movement of a chemical.

false

Cilia and flagella project from the cell and are not covered by cytoplasmic membrane. ⊚ true ⊚ false

A) Penicillin will likely have a greater effect on the wall shown in panel A, which shows a Gram-positive cell wall.

Consider the figure. Select the CORRECT statement regarding penicillin and the bacterial cell wall. A) Penicillin will likely have a greater effect on the wall shown in panel A, which shows a Gram-positive cell wall. B) Penicillin will likely have a greater effect on the wall shown in panel A, which shows a Gram-negative cell wall. C) Penicillin will likely have a greater effect on the wall shown in panel B, which shows a Gram-negative cell wall. D) Penicillin will likely have a greater effect on the wall shown in panel B, which shows a Gram-positive cell wall. E) Penicillin will always have an equal effect on the cell walls shown in panel A and panel B .

A) The membrane is the permeability barrier that defines the cell boundary, while the wall provides strength to the cell to prevent it from lysing.

How does the function of the cell membrane differ from that of the cell wall? A) The membrane is the permeability barrier that defines the cell boundary, while the wall provides strength to the cell to prevent it from lysing. B) The cell wall is the permeability barrier that defines the cell boundary, while the cell membrane provides strength to the cell to prevent it from lysing. C) The cell membrane and the cell wall have the identical function: they confer specific shape to the organism and control substances entering and leaving it. D) The cell membrane defines the boundary of the cell, while the only function of the cell wall is to provide a means to identify different types of bacteria. E) The cell wall is the pemeable boundary of the cell while the cell membrane is the impermeable boundary of the cell.

A) a hypertonic environment.

If a cell is placed into a solution and water leaves the cell, the cell is in A) a hypertonic environment. B) hypotonic environment. C) isotonic environment. D) anoxygenic environment. E) even environment.

B) Smear, fix, stain

In a basic staining procedure, which is the correct order of steps? A) Fix, smear, stain B) Smear, fix, stain C) Fix, stain, decolorize D) Smear, decolorize, stain E) Smear, stain, fix

A) is Gram-negative.

In the name E. coli O157:H7, "O157" refers to O antigen. From this, you can conclude that E. coli A) is Gram-negative. B) is Gram-positive. C) is a pathogen. D) is a coccus. E) has a capsule.

C) decrease the refraction AND increase the resolution.

In viewing a microscopic specimen, oil is used to A) increase the refraction AND increase the reflection. B) decrease the refraction AND increase the reflection. C) decrease the refraction AND increase the resolution. D) increase the reflection AND increase the resolution. E) increase the resolution AND increase the refraction.

C) atomic force microscope.

Individual atoms on the surface of prepared samples can be observed by using the A) scanning electron microscope. B) dark-field microscope. C) atomic force microscope. D) phase contrast microscope. E) light microscope.

true

LPS is found in the outer membrane of Gram-negative bacteria. ⊚ true ⊚ false

false

Lysosomes are bags of digestive enzymes found in prokaryotic cells. ⊚ true ⊚ false

D) stained pink and are cylindrical in shape.

Petrus brings his 87-year old grandmother to the emergency department where you work. His grandmother has a fever, is dehydrated and confused, and complains of pain when urinating. Petrus reports that she has not been eating or drinking, but she has no signs or symptoms of gastrointestinal distress. You request blood samples and also a urine sample. You decide to keep Petrus' grandmotherin the hospitalso that she can be given intravenous fluids. You also want to wait for the lab test results before you decide whether she required additional treatment or if she can return home. When Petrus' grandmother's test results are sent to you, you discover that while her blood work is normal, her urine has Gram-negative bacilli in it. Based on this, you know that the cells are A) stained blue and are cylindrical in shape. B) stained purple and are cylindrical in shape. C) stained pink and are spherical in shape. D) stained pink and are cylindrical in shape. E) stained green and are oval in shape.

C) Bacillus and Clostridium - endospores

Please select the CORRECT pair regarding prokaryote cell structure and microscopy. A) Transmission electron microscope - surface details B) 70S ribosomes - protozoa C) Bacillus and Clostridium - endospores D) Peptidoglycan - bacteria and archaea E) Gram-positive cells - O antigen

D) Capsules and slime layers - phospholipids

Please select the MISMATCHED pair regarding prokaryotes, microscopes and staining. A) Light microscope - 1,000-fold magnification B) Acid fast stain - differential C) Mycoplasmapneumoniae- pleomorphic cells D) Capsules and slime layers - phospholipids E) Membrane-bound organelles - fungi

A) Some archeae have pseudopeptidogylcan in their cell walls.

Please select the TRUE statement regarding cell walls of Archaea. A) Some archeae have pseudopeptidogylcan in their cell walls. B) Some archeae have peptidoglycan in their cell walls but most do not. C) Archaea do not have cell walls; they have only cell membranes. D) The archaeal cell wall is highly sensitive to penicillin. E) The archaeal cell wall resembles a Gram-negative bacterial cell wall.

false

Prokaryotes may ingest particles via phagocytosis. ⊚ true ⊚ false

B) They have a positive charge.

Select the CORRECT statement regarding basic dyes. A) They have a negative charge. B) They have a positive charge. C) They are electrically neutral. D) They contain both positively and negatively charged particles. E) They are always blue or purple.

C) Eukaryote cell are defined by the presence of a membrane bound nucleus.

Select the CORRECT statement regarding eukaryotic cells. A) Eukaryotic cell are less complex than prokaryotic cells. B) They are members of the domains Bacteria and Archaea. C) Eukaryote cell are defined by the presence of a membrane bound nucleus. D) They are able to divide more rapidly than prokaryotic cells. E) Eukaryoticcell are defined by the presence of a cell wall.

E) Capsules take up stains well.

Select the FALSE statement regarding capsules. A) Capsules may increase an organism's ability to cause disease. B) Capsules are typically "negatively" stained. C) Capsules may be stained as a wet mount. D) Capsules are usually composed of polysaccharides. E) Capsules take up stains well.

A) increase resolution.

Under standard conditions, the best way to observe more details in a microscopic specimen is to A) increase resolution. B) increase magnification. C) decrease magnification. D) increase scatter. E) decrease resolution.

A) Alcohol

When doing a Gram stain, leavingwhich of the following on for twice as long as directed would have the most significant consequence? A) Alcohol B) Crystal violet C) Iodine D) Safranin E) Carbol fuchsin

C) Diaminopimelic acid

Which amino acid is found only in the cell walls of bacteria? A) Glycerol B) L-form of glycine C) Diaminopimelic acid D) L-form of methionine E) D-form of methionine

B) They are found in all organisms.

Which is NOT true of mitochondria and chloroplasts? A) They contain DNA and 70S ribosomes. B) They are found in all organisms. C) They are capable of performing protein synthesis. D) They generate ATP. E) They are membrane-bound organelles.

C) It consists mainly of a fixed, static, phospholipid bilayer.

Which is NOT true of the cytoplasmic membrane? A) It defines the boundaries of the cell. B) It is a selectively permeable barrier. C) It consists mainly of a fixed, static, phospholipid bilayer. D) It contains proteins used as selective gates and sensors. E) All of the answer choices are true.

A) Water usually enters a cell and produces a high osmotic pressure.

Which is TRUE of simple diffusion of water? A) Water usually enters a cell and produces a high osmotic pressure. B) Water usually leaves the cell and produces negative osmotic pressure. C) Water tends to enter and leave the cell equally, resulting in no pressure in the cell. D) Waterdiffusion ultimately relies on the selectively permeable nature of the cell wall. E) Water usually enters a cell and produces a very low osmotic pressure.

B) It is useful for distinguishing a small group of organisms, including Mycobacterium AND it uses carbolfuchsin and methylene blue.

Which statements are TRUE for the acid-fast stain? A) It is useful for distinguishing a small group of organisms, including MycobacteriumAND it reflects differences in cytoplasmic membrane structure. B) It is useful for distinguishing a small group of organisms, including Mycobacterium AND it uses carbolfuchsin and methylene blue. C) It is useful for distinguishing a small group of organisms, including Mycobacterium AND it uses carbolfuchsin and safranin. D) It is useful for distinguishing a small group of organisms, including MycoplasmaAND it uses carbolfuchsin and methylene blue. E) It is useful for distinguishing a small group of organisms, including Bacillus AND it uses crystal violet and safranin.

C) Coccus AND Bacillus

Which terms refer to bacterial morphology? A) Bacillus AND polyhedral B) Coccus AND polyhedral C) Coccus AND Bacillus D) Polyhedral, coccus, AND Bacillus E) Coccus AND squarish

B) Electrons are particles, and particles cannot travel through a solid item. The hole in the middle allows them to travel from the source of the electrons to the specimen.

Why are the lenses of anelectron microscopeshaped like donuts (with a hole in the middle) rather than solid, like the lenses in a light microscope? A) A magnetic field cannot be applied across a completely solid object—there must be an opening within the object for the field to be applied through. B) Electrons are particles, and particles cannot travel through a solid item. The hole in the middle allows them to travel from the source of the electrons to the specimen. C) The electronswould destroy the electromagnet material unless there was a physical hole forthem to travel through on their way to the specimen. D) The user has to be able to physically look through the magnets to focus the beam of electrons onto the specimen, since the metal of the magnets is opaque. Without a hole in the middle, the user wouldn't be able to see! E) All of the answer choices are correct.

A) To fix (attach) the bacteria to the microscope slide.

Why is a bacterial smear heated before staining? A) To fix (attach) the bacteria to the microscope slide. B) To kill the bacteria to make them harmless. C) To remove any capsules that would affect the staining method. D) To make the cell wall porous so dye can enter the cell. E) To differentiate between Gram-positive and Gram-negative cells.

C) Prokaryote ribosomes and eukaryote ribosomes are different.

Why is it possible to use an antibiotic to target prokaryote protein synthesis without affecting eukaryote protein synthesis? A) Eukaryotes do not carry out protein synthesis or cell wall synthesis. B) Eukaryotes do not contain cell walls of peptidoglycan. C) Prokaryote ribosomes and eukaryote ribosomes are different. D) Prokaryotes do not contain mitochondria or Golgi apparatus. E) All prokaryotes are unicellular while eukaryotes can be uni- or multicellular.

A) Electrons are particles but there are other particles in air as well. Without a vacuum, the electrons would strike and be scattered by the particles within the air.

Why must the lenses and specimenbe in a vacuum when usingan electron microscope? A) Electrons are particles but there are other particles in air as well. Without a vacuum, the electrons would strike and be scattered by the particles within the air. B) Electrons are highly radioactive, and the chamber must be completely sealed and under vacuum to prevent them from escaping and contaminating the lab area. C) The vacuum fixing the specimen to the slide grid. Without fixing the specimen by vacuum, it would slide off and we wouldn't be able to visualize it. D) The vacuum bends rays of visible light through the lenses and specimen so that details of the specimen can be clearly vizualized from all angles. E) None of the answer choices is true.

A) Gram-positive streptococcus.

You correctly Gram-stain an unknown bacterium in your microbiology laboratory and see chains of purple spherical cells. Based on this information you can conclude that this organism is a A) Gram-positive streptococcus. B) Gram-negative streptoccocus. C) Gram-positive sphere. D) Gram-negative streptobacillus. E) Gram-negative diplococcus.

B) has a capsule.

You discover a new pathogen which you visualize using a light microscope. A negative stain reveals a clear halo around the cells. This suggests to you that the organism A) is motile. B) has a capsule. C) is spherical in shape. D) is Gram-positive. E) has an LPS layer

B) Rod-shaped bacterium with a thick cell wall, a capsule, and flagella distributed over its surface, that can form endosporesfor survival of adverse conditions.

You discover an encapsulatedGram-positive, peritrichous, spore-forming bacillus. Which of the following describes the organism? A) Sphericalbacterium with a thin cell wall, a slime layer, and flagella distributed over ts surface, that can form endosporesfor survival of adverse conditions. B) Rod-shaped bacterium with a thick cell wall, a capsule, and flagella distributed over its surface, that can form endosporesfor survival of adverse conditions. C) Sphericalbacterium with a thick cell wall, a slime layer, and a single flagellum at one side of the cell. D) Rod-shaped bacterium with a thin cell wall, a capsule, and single flagellum at one end, that can form endosporesfor survival in adverse conditions. E) Rod-shaped bacterium with a thin cell wall, a slime layer, and single flagellum at one end, that can form endosporesfor survival in adverse conditions.

A) Sample A - Gram-negative cell; Sample B - Gram-positive cell; Sample C - Mycoplasma

You do a chemical analysis of three bacterial samples. In one (sample A), you find phospholipids, peptidoglycan, O antigen and lipid A. In the second(sample B) you find peptidoglycan, phospholipids and teichoic acids. In the third (sample C)you find phospholipids but no peptidoglycan. Select the TRUE statement. A) Sample A - Gram-negative cell; Sample B - Gram-positive cell; Sample C - Mycoplasma B) Sample A - Gram-positive cell; Sample B - Gram-negative cell; Sample C - Mycoplasma C) Sample A - Gram-negative cell; Sample B - Gram-positive cell; Sample C - prion D) Sample A - Gram-negative cell; Sample B - Gram-positive cell; Sample C - Streptococcus E) Sample A - Gram-positive cell; Sample B - Gram-negative cell; Sample C - Mycobacterium

B) An atomic force microscope—this has the highest resolution and magnification of the microscopes we discussed andwe want to visualize a subcomponent of the virus particles.

You want to examine the structure of the protein coat of a virus by microscopy. Which microscope is your best choice, and why? A) The scanning electron microscope—it has excellent resolution and magnification (much higher than a light microscope), and can clearly visualize viruses. B) An atomic force microscope—this has the highest resolution and magnification of the microscopes we discussed andwe want to visualize a subcomponent of the virus particles. C) A fluorescent microscope—this will let us tag the virus protein coat with colored dyes in order to visualize it using this light microscope at 1000x. D) A bright-field light microscope—of course, we'll need to stain the viruses before we can visualize them against the bright white background at 1000x total magnification. E) The phase-contrast microscope—it has excellent contrast and magnification, and can be used to visualize viruses very clearly.

A) Disconnecting and bringing in the old, mildewed showerhead from your bathroom.

Your instructor wants you to bring in an example of a biofilm to your lab. Which choice is the best selection for bringing in an INTACT biofilm for further study? A) Disconnecting and bringing in the old, mildewed showerhead from your bathroom. B) Scraping the mold offthe shower curtain in yourbathroom into a paper cup using a butter knife. C) Using a toothpick to scrape plaque off of your teeth and smearing it onto a slide to bring in to lab. D) Wiping a sponge across a slimy boulder in a stream in a nearby park and bringing it in to lab. E) Wiping a sponge across your dog's teeth, smearing it onto a glass slide and bringing it in to lab.