BIO 120 MIDTERM Practice Q's
Which of the following places the steps in the correct sequence? 1-Staining 2-Making a smear 3-Fixing A) 1-2-3 B) 3-2-1 C) 2-3-1 D) 1-3-2 E) The order is unimportant.
C) 2-3-1
Which of the following places the steps of the Gram stain in the correct order? 1-Alcohol-acetone 2-Crystal violet 3-Safranin 4-Iodine A) 1-2-3-4 B) 2-1-4-3 C) 2-4-1-3 D) 4-3-2-1 E) 1-3-2-4
C) 2-4-1-3
Which type of stain is most useful in helping clinicians to decide which antibiotic to prescribe for a bacterial infection? A) negative stain B) simple stain C) Gram stain D) endospore stain E) flagella stain
C) Gram stain
Which of the following statements best describes what happens when a bacterial cell is placed in a solution containing 5% NaCl? A) Sucrose will move into the cell from a higher to a lower concentration. B) The cell will undergo osmotic lysis. C) Water will move out of the cell. D) Water will move into the cell. E) No change will result; the solution is isotonic.
C) Water will move out of the cell.
By which of the following mechanisms can a cell transport a substance from a lower to a higher concentration? A) simple diffusion B) facilitated diffusion C) active transport D) extracellular enzymes E) aquaporins
C) active transport
By which of the following mechanisms can a cell transport a substance from a lower to a higher concentration? A) simple diffusion B) facilitated diffusion C) active transport D) extracellular enzymes E) aquaporins
C) active transport
A definitive host harbors which stage of a parasite? A) miracidium B) cyst C) adult D) larva E) All of the answers are correct.
C) adult
Oncogenic viruses A) cause acute infections. B) are genetically unstable. C) cause tumors to develop. D) are lytic viruses that kill the host cell. E) have no effect on the host cell.
C) cause tumors to develop.
You are performing a Gram stain on gram-negative bacteria and you stop after the decolorizer step. What is the appearance of the bacteria at this point? A) purple B) red C) colorless D) brown
C) colorless
This microscope produces an image of a light cell against a dark background; internal structures are NOT visible. A) compound light microscope B) phase-contrast microscope C) darkfield microscope D) fluorescence microscope E) electron microscope
C) darkfield microscope
Which of the following pairs is mismatched? A) confocal microscope - produces a three-dimensional image B) darkfield microscope - uses visible light C) fluorescence microscope - uses a fluorescent light D) scanning electron microscope - produces a three-dimensional image E) scanning tunneling microscope - allows visualization of atoms
C) fluorescence microscope - uses a fluorescent light
Which of the following methods is used to preserve food by slowing the metabolic processes of foodborne microbes? A) lyophilization B) nonionizing radiation C) freezing D) ionizing radiation E) pasteurization
C) freezing
Helminthic diseases are usually transmitted to humans by A) respiratory route. B) genitourinary route. C) gastrointestinal route. D) vectors. E) aerosols.
C) gastrointestinal route.
Which of the following arthropods does NOT transmit diseases by sucking blood from a human host? A) lice B) fleas C) houseflies D) mosquitoes E) kissing bugs
C) houseflies
Lysogeny can result in all of the following EXCEPT: A) immunity to reinfection by the same phage. B) acquisition of new characteristics by the host cell. C) immunity to reinfection by any phage. D) specialized transduction. E) phage conversion.
C) immunity to reinfection by any phage.
If a larva of Echinococcus granulosus is found in humans, humans are the A) definitive host. B) infected host. C) intermediate host. D) reservoir. E) None of the answers is correct.
C) intermediate host.
The DNA found in most bacterial cells A) is surrounded by a nuclear membrane B) utilizes histones for chromosomal packaging C) is circular in structure D) is linear in structure. E) is found in multiple copies
C) is circular in structure
A disease in which the causative agent remains inactive for a time before producing symptoms is referred to as A) subacute. B) subclinical. C) latent. D) zoonotic. E) acute.
C) latent.
A commensal bacterium A) does not receive any benefit from its host. B) is beneficial to its host. C) may also be an opportunistic pathogen. D) isn't capable of causing disease in its host. E) always causes disease in its host.
C) may also be an opportunistic pathogen.
Which of the following may result from systemic anaphylaxis? A) hay fever B) asthma C) shock D) hives E) immunodeficiency
C) shock
In the name Staphylococcus aureus, aureus is the? A) genus B) domain name C) species D) kingdom E) Family name
C) species
Recombinant DNA technology has become an increasingly important part of our life. It is used for all of the following EXCEPT A) vaccine production B) enhancing food longevity. C) synthesis of water D) drug production E) increasing the nutritional value of food.
C) synthesis of water
A persistent infection is one in which A) the virus remains in equilibrium with the host without causing a disease. B) viral replication is unusually slow. C) the disease process occurs gradually over a long period. D) host cells are gradually lysed. E) host cells are transformed.
C) the disease process occurs gradually over a long period.
The resolution of a microscope can be improved by changing the A) condenser B) fine adjustment C) wavelength of light D) diaphragm E) coarse adjustment.
C) wavelength of light
The formal system for classifying and naming organisms was developed by A) Robert Koch B) Ignaz Semmelweis C) Aristotle D) Carolus Linnaeus E) Louis Pasteur
D) Carolus Linnaeus
The formal system for classifying and naming organisms was developed by A) Robert Koch. B) Ignaz Semmelweis. C) Aristotle. D) Carolus Linnaeus. E) Louis Pasteur.
D) Carolus Linnaeus.
Which of the following is a limitation of the autoclave? A) It requires an excessively long time to achieve sterilization. B) It cannot inactivate viruses. C) It cannot kill endospores. D) It cannot be used with heat-labile materials. E) It cannot be used with glassware.
D) It cannot be used with heat-labile materials.
Which of the following statements about gram-negative cell walls is FALSE? A) They protect the cell in a hypotonic environment. B) They have an extra outer layer composed of lipoproteins, lipopolysaccharides, and phospholipids. C) They are toxic to humans. D) They are sensitive to penicillin. E) Their Gram reaction is due to the outer membrane.
D) They are sensitive to penicillin.
How do all viruses differ from bacteria? A) Viruses are filterable. B) Viruses are obligate intracellular parasites. C) Viruses do not have any nucleic acid. D) Viruses are not composed of cells. E) Viruses do not reproduce.
D) Viruses are not composed of cells.
Which one of the following statements is a reason for NOT classifying viruses in one of the three domains of life (Bacteria, Archaea, Eukarya) rather than in a fourth separate domain? A) Some viruses can incorporate their genome into a host's genome. B) Viruses direct anabolic pathways of host cells. C) Viruses are obligate parasites. D) Viruses are not composed of cells.
D) Viruses are not composed of cells.
Most bacteria reproduce by A) aerial hyphae. B) fragmentation. C) mitosis. D) binary fission. E) budding.
D) binary fission.
Bacteria and Archaea are similar in which of the following? A) peptidoglycan cell walls B) methionine as the start signal for protein synthesis C) sensitivity to antibiotics D) considered prokaryotic cells E) plasma membrane ester linkage
D) considered prokaryotic cells
Application of heat to living cells can result in all of the following EXCEPT: A) breaking of hydrogen bonds. B) alteration of membrane permeability. C) denaturation of enzymes. D) decreased thermal death time. E) damage to nucleic acids.
D) decreased thermal death time.
Which microscope is used to observe a specimen that emits light when illuminated with an ultraviolet light? A) compound light microscope B) phase-contrast microscope C) darkfield microscope D) fluorescence microscope E) electron microscope
D) fluorescence microscope
Salts and sugars work to preserve foods by creating a A) depletion of nutrients. B) hypotonic environment. C) lower osmotic pressure. D) hypertonic environment. E) lower pH.
D) hypertonic environment.
Bacteriophage replication differs from animal virus replication because only bacteriophage replication involves A) adsorption to specific receptors. B) assembly of viral components. C) replication of viral nucleic acid. D) injection of naked nucleic acid into the host cell. E) lysis of the host cell.
D) injection of naked nucleic acid into the host cell.
A bacterial species differs from a species of eukaryotic organisms in that a bacterial species A) does not breed with other species. B) has a limited geographical distribution. C) can be distinguished from other bacterial species. D) is a population of cells with similar characteristics. E) breeds with its own species.
D) is a population of cells with similar characteristics.
Which of the following is NOT a direct method to measure microbial growth? A) direct microscopic count B) standard plate count C) filtration on a support membrane followed by incubation on medium D) metabolic activity E) most probable number (MPN)
D) metabolic activity
The major significance of Robert Koch's work is that A) microorganisms are present in a diseased animal. B) diseases can be transmitted from one animal to another. C) microorganisms can be cultured. D) microorganisms cause disease. E) microorganisms are the result of disease.
D) microorganisms cause disease.
The term used to describe a disease-causing microorganism is A) microbe B) bacterium C) virus D) pathogen E) infection
D) pathogen
In a hypertonic solution, a bacterial cell will typically A) lyse B) burst C) stay the same. D) plasmolyze E) osmolyze.
D) plasmolyze
The purpose of a mordant in the Gram stain is to A) remove the simple stain. B) make the bacterial cells larger C) make the flagella visible. D) prevent the crystal violet from leaving the cells. E) make gram-negative cells visible.
D) prevent the crystal violet from leaving the cells.
The difference between simple diffusion and facilitated diffusion is that facilitated diffusion A) moves materials from a higher to a lower concentration B) moves materials from a lower to a higher concentration C) requires ATP. D) requires transporter proteins E) does not require ATP.
D) requires transporter proteins
Most of the normal microbiota of the digestive system are found in the A) mouth. B) stomach. C) stomach and small intestine. D) small intestine and large intestine. E) accessory structures.
D) small intestine and large intestine.
What is the total magnification of a specimen viewed with a 10x ocular lens and a 45x objective lens? A) 4.5x B) 10x C) 45x D) 100x E) 450x
E) 450x
Recombinant DNA refers to the A) study of bacterial ribosomes. B) study of the function of genes. C) interaction between human and bacterial cells. D) synthesis of proteins from genes. E) DNA resulting when genes from one organism are inserted into another organism.
E) DNA resulting when genes from one organism are inserted into another organism.
All cells possess a cell wall. TRUE OR FALSE
FALSE
Desiccation is a reliable form of sterilization. TRUE OR FALSE
FALSE
In a completed Gram stain, gram-negative bacteria are colorless. TRUE OR FALSE
FALSE
In helminth life cycles, the organism that harbors the adult sexually reproductive phase of the parasite is called the intermediate host. TRUE OR FALSE
FALSE
In measuring turbidity of a culture in indirect measurement of bacterial growth, absorbance and transmittance are identical and interchangeable values. TRUE OR FALSE
FALSE
Most pathogenic bacteria are thermophiles TRUE OR FALSE
FALSE
The process of pasteurization to reduce food spoilage utilizes high heat to kill all bacteria present. TRUE OR FALSE
FALSE
Viruses are the only known infectious agents that are obligatory intracellular parasites. TRUE OR FALSE
FALSE
Penicillin was discovered by accident by A) Alexander Fleming. B) Ehrlich. C) Edward Jenner. D) Robert Koch. E) Joseph Lister.
A) Alexander Fleming.
Anaphylaxis is the term for reactions caused when certain antigens combine with A) IgE antibodies. B) macrophages. C) IgG antibodies. D) complement. E) histamine.
A) IgE antibodies.
The arguments supporting spontaneous generation were finally disproved by A) Louis Pasteur. B) Francesco Redi. C) Rudolf Virchow. D) John Needham. E) Lazzaro Spallanzani.
A) Louis Pasteur.
Which of the following statements regarding fungi is FALSE? A) Most fungi are pathogenic for humans. B) Fungi are eukaryotic heterotrophs. C) Fungi reproduce by forming asexual or sexual spores. D) Most fungi grow well in acidic culture condition. E) Fungi tolerate low moisture conditions.
A) Most fungi are pathogenic for humans.
Which of the following best describes the pattern of microbial death? A) The cells in a population die at a constant rate. B) All the cells in a culture die at once. C) Not all of the cells in a culture are killed. D) The pattern varies depending on the antimicrobial agent. E) The pattern varies depending on the species.
A) The cells in a population die at a constant rate.
A lytic virus has infected a patient. Which of the following would best describe what is happening inside the patient? A) The virus is causing the death of the infected cells in the patient B) The virus is not killing any cells in the host C) The virus is incorporating its nucleic acid with that of the patient's cells D) The virus is slowly killing the patient's cells E) The virus is infecting cells and then releasing only small amounts of virus
A) The virus is causing the death of the infected cells in the patient.
Which of the following is NOT a domain in the three-domain system? A) animalia B) archaea C) bacteria D) eukarya
A) animalia
Viruses are not considered living organisms because they A) cannot reproduce by themselves B) are structurally very simple C) can only be visualized using an electron microscope D) are typically associated with disease E) are ubiquitous in nature
A) cannot reproduce by themselves
Simple staining is often necessary to improve contrast in which microscope? A) compound light microscope B) phase-contrast microscope C) darkfield microscope D) fluorescence microscope E) electron microscope
A) compound light microscope
The term aerotolerant anaerobe refers to an organism that A) does not use oxygen but tolerates it. B) is killed by oxygen. C) tolerates normal atmospheric nitrogen gas levels. D) requires less oxygen than is present in air. E) requires more oxygen than is present in air.
A) does not use oxygen but tolerates it.
The chemical mediators of anaphylaxis are A) found in basophils and mast cells. B) antibodies. C) antigens. D) antigen-antibody complexes. E) the proteins of the complement system.
A) found in basophils and mast cells.
Ringworm is caused by a(n) A) fungus. B) cestode. C) nematodes. D) protozoan. E) trematode.
A) fungus.
Lysogenic bacteriophages contribute to bacterial virulence because bacteriophages A) give new gene sequences to the host bacteria. B) produce toxins. C) carry plasmids. D) kill the bacteria, causing release of endotoxins. E) kill human cells.
A) give new gene sequences to the host bacteria.
Archaea differ from bacteria in that archaea A) have cell walls composed of substances other than peptidoglycan. B) lack nuclei. C) use organic compounds for food. D) reproduce by binary fission. E) are prokaryotic.
A) have cell walls composed of substances other than peptidoglycan.
Archaea differ from bacteria in that archaea A) have cell walls composed of substances other than peptidoglycan. B) lack nuclei. C) use organic compounds for food. D) reproduce by binary fission. E) are prokaryotic.
A) have cell walls composed of substances other than peptidoglycan.
The best description of direct damage by a pathogen is A) host cells destroyed when pathogens metabolize and multiply. B) capsule components of pathogens kill cells. C) poisonous substances secreted by viruses kill cells. D) superantigens cause cytokine release which then cause symptoms of disease. E) protein synthesis is interrupted by toxins.
A) host cells destroyed when pathogens metabolize and multiply.
Some viruses, such as human herpesvirus 1, infect a cell without causing symptoms. These are called A) latent viruses. B) lytic viruses. C) phages. D) slow viruses. E) unconventional viruses.
A) latent viruses.
Which of the following correctly traces the path of light through the compound microscope? A) light source; condenser; specimen; objective lens; ocular lens B) condenser; light source; specimen; ocular lens; objective lens C) light source; specimen; condenser; objective lens; ocular lens D) condenser; light source; specimen; objective lens; ocular lens E) light source; condenser; objective lens; specimen; ocular lens
A) light source; condenser; specimen; objective lens; ocular lens.
The definition of lysogeny is A) phage DNA is incorporated into host cell DNA. B) lysis of the host cell due to a phage. C) the period during replication when virions are not present. D) when the burst time takes an unusually long time. E) attachment of a phage to a cell.
A) phage DNA is incorporated into host cell DNA.
You are performing a Gram stain on gram-positive bacteria and you stop after the addition of the first dye. What is the appearance of the bacteria at this point? A) purple/blue B) red C) colorless D) brown
A) purple/blue
Shingles in an example of A) reactivation of latent virus. B) lytic virus. C) persistent virus. D) lysogeny. E) transformation.
A) reactivation of latent virus.
Which of the following places these items in the correct order for DNA-virus replication? 1. Maturation 2. DNA synthesis 3. Transcription 4. Translation A) 1; 2; 3; 4 B) 2; 3; 4; 1 C) 3; 4; 1; 2 D) 4; 1; 2; 3 E) 4; 3; 2; 1
B) 2; 3; 4; 1
Which concentration of ethanol is the most effective bactericide? A) 100 percent B) 70 percent C) 50 percent D) 40 percent E) 30 percent
B) 70 percent
You discovered a unicellular organism that lacks a nucleus and peptidoglycan. You suspect the organism is in the group A) Animalia. B) Archaea. C) Bacteria. D) Fungi. E) Plantae.
B) Archaea.
You discovered a unicellular organism that lacks a nucleus and peptidoglycan. You suspect the organism is in the group: A) Animalia. B) Archaea. C) Bacteria. D) Fungi. E) Plantae.
B) Archaea.
Into which group would you place a unicellular organism that has 70S ribosomes and a peptidoglycan cell wall? A) Animalia B) Bacteria C) Fungi D) Plantae E) Protist
B) Bacteria
Which physician is first associated with vaccination? A) Ehrlich B) Jenner C) Lister D) Koch E) Escherich
B) Jenner
Which step in the Gram stain is the critical step in differentiating gram-positive cells from gram-negative cells? A) safranin B) alcohol-acetone C) iodine D) crystal violet
B) alcohol-acetone
Serological testing is based on the fact that A) all bacteria have the same antigens. B) antibodies react specifically with an antigen. C) the human body makes antibodies against bacteria. D) antibodies cause the formation of antigens. E) bacteria clump together when mixed with any antibodies.
B) antibodies react specifically with an antigen.
The mechanism whereby an enveloped virus leaves a host cell is called A) transduction. B) budding. C) abduction. D) lysogeny. E) penetration.
B) budding.
An example of a latent viral infection is A) subacute sclerosing panencephalitis. B) cold sores. C) influenza. D) smallpox. E) mumps.
B) cold sores.
Which of the following is NOT utilized to culture viruses? A) laboratory animals B) culture media C) embryonated eggs D) animal cell cultures E) bacterial cultures
B) culture media
Biogenesis refers to the A) spontaneous generation of organisms from nonliving matter. B) development of life forms from preexisting life forms. C) development of aseptic technique. D) germ theory of disease.
B) development of life forms from preexisting life forms.
The ________ method is used to indirectly measure microbial growth of filamentous bacteria and molds. A) metabolic activity B) dry weight C) pour plate D) spread plate E) turbidity measurement
B) dry weight
Which of the following is an example of a metabolic activity that could be used to measure microbial growth? A) standard plate count B) glucose consumption C) direct microscopic count D) turbidity E) most probable number (MPN)
B) glucose consumption
Microbes that live stably in and on the human body are called the A) transient microbiota B) human microbiome C) pathogenic microorganisms D) virulent microorganisms E) opportunistic microbiota
B) human microbiome
The purpose of the ocular lens is to A) improve resolution B) magnify the image from the objective lens C) decrease the refractive index D) increase the light E) decrease the light
B) magnify the image from the objective lens
Which of the following does NOT achieve sterilization? A) dry heat B) pasteurization C) autoclave D) supercritical fluids E) ethylene oxide
B) pasteurization
Which microscope is used to see internal structures of cells in a natural state? A) compound light microscope B) phase-contrast microscope C) darkfield microscope D) fluorescence microscope E) electron microscope
B) phase-contrast microscope
A virus's ability to infect an animal cell depends primarily upon the A) host cell's ability to phagocytize viral particles. B) presence of receptor sites on the cell membrane. C) type of viral nucleic acid. D) enzymatic activity of a host cell. E) presence of pili on the host cell wall.
B) presence of receptor sites on the cell membrane.
An infectious protein is a A) bacteriophage. B) prion. C) retrovirus. D) viroid. E) papovavirus.
B) prion.
Oxygen crosses a plasma membrane A) by osmosis B) through simple diffusion C) with the help of a nonspecific transporter D) through facilitated diffusion. E) through porins.
B) through simple diffusion
Which of the following statements is correct about passive diffusion? A) It requires an expenditure of energy by the cell. B) It is a process in which molecules move from a region of higher concentration to a region of lower concentration (or down a concentration gradient). C) It is a process in which molecules move from a region of lower concentration to one of higher concentration (or up a concentration gradient). D) It may require a transport protein. E) It involves movement of molecules down a concentration gradient and may require a transport protein.
E) It involves movement of molecules down a concentration gradient and may require a transport protein.
Which of the following is NOT a reservoir of infection? A) a sick person B) a healthy person C) a sick animal D) a hospital E) None of the answers is correct; all of these can be reservoirs of infection.
E) None of the answers is correct; all of these can be reservoirs of infection.
An example of a persistent viral infection is A) Hepatitis A infection. B) Influenza. C) Herpes Simplex Virus infection. D) Human Immunodeficiency Virus infection. E) Varicella Virus infection.
E) Varicella Virus infection.
Which microscope achieves the highest magnification and greatest resolution? A) compound light microscope B) phase-contrast microscope C) darkfield microscope D) fluorescence microscope E) electron microscope
E) electron microscope
Which microscope is used to see detail of a 300-nm virus? A) fluorescence microscope B) phase-contrast microscope C) darkfield microscope D) DIC microscope E) electron microscope
E) electron microscope
In the malaria parasite life cycle, humans are the ________ host, while mosquitoes are the ________ host as well as the vector. A) definitive; intermediate B) intermediate; intermediate C) temporary; final D) vector; intermediate E) intermediate; definitive
E) intermediate; definitive
Leukotrienes are inflammatory vasoactive mediators produced by A) neutrophils. B) eosinophils. C) skin cells. D) macrophages. E) mast cells and basophils.
E) mast cells and basophils.
Mycology is the study of A) mycoplasma. B) mushrooms. C) protozoa. D) molds. E) molds, yeast, and mushrooms.
E) molds, yeast, and mushrooms.
Which of the following contributes to the virulence of a pathogen? A) numbers of microorganisms that gain access to a host B) evasion of host defenses C) toxin production D) numbers of microorganisms that gain access to a host and evasion of host defenses E) numbers of microorganisms that gain access to a host, evasion of host defenses, and toxin production
E) numbers of microorganisms that gain access to a host, evasion of host defenses, and toxin production
Each of the following is caused by prions EXCEPT: A) sheep scrapie. B) kuru C) Creutzfeldt-Jakob disease. D) bovine spongiform encephalopathy. E) rabies.
E) rabies.
An envelope is acquired during which of the following steps? A) penetration B) adsorption C) uncoating D) biosynthesis E) release
E) release
Which of the following definitions is INCORRECT? A) acute: a short-lasting primary infection B) inapparent: infection characteristic of a carrier state C) chronic: a disease that develops slowly and lasts for months D) primary infection: an initial illness E) secondary infection: a long-lasting illness
E) secondary infection: a long-lasting illness
All of the following occur during inflammation. What is the first step? A) diapedesis B) margination C) phagocyte migration D) repair E) vasodilation
E) vasodilation
Autoclaving is the most effective method of moist heat sterilization TRUE OR FALSE
TRUE
Bacterial growth refers to an increase in the numbers of cells in a bacterial culture. TRUE OR FALSE
TRUE
Cells placed in a hypertonic solution tend to lose water due to osmotic pressure TRUE OR FALSE
TRUE
Cells viewed in darkfield microscopy appear similar to those stained with the negative stain. TRUE OR FALSE
TRUE
In a completed Gram stain, gram-positive bacteria are purple. TRUE OR FALSE
TRUE
Prokaryotes lack organelles TRUE OR FALSE
TRUE
The basic mechanism of viral multiplication is similar for all viruses. TRUE OR FALSE
TRUE
The cell walls of bacteria are responsible for the shape of the bacteria and the difference in the Gram stain reaction TRUE OR FALSE
TRUE
The thermal death time is the time needed to kill all the bacteria in a particular culture at a certain temperature. TRUE OR FALSE
TRUE
The varicella-zoster virus is the causative agent of chickenpox and shingles. TRUE OR FALSE
TRUE
