Question

Which of the following microorganisms lack mitochondria? a. Fungi b. Bacteria c. Parasites d. Protists Which bacteria have cell walls that are approximately 10-20% peptidoglycan? a. Gram-positive b. Gram-negative c. Acid-fast d. Wall-deficient Which bacteria are difficult to Gram stain? a. Gram-positive b. Gram-negative c. Acid-fast d. Wall-deficient Which of the following types of bacteria are slow growing, due to the high lipid content of their cell walls? a Gram-positive b Gram-negative c. Acid-fast d. Wall-deficient Which of the following types of bacteria have strong cellular membranes that contain sterols? a Gram-positive b. Gram-negative c. Acid-fast d. Wall-deficient Which of the following types of bacteria have both a cell membrane and an outer membrane? a. Gram-positive b. Gram-negative c. Acid-fast d. Wall-deficient Which of the following is an endotoxin, which can cause fever and inflammation, and is associated with Gram-negative bacteria? a. Teichoic acid b. Periplasmic space c. Peptidoglycan d. Lipopolysaccharide Which of the following structures is associated with Gram-negative bacteria and is an active area of cell metabolism? a. Teichoic acid b. Periplasmic space c. Peptidoglycan d. Lipopolysaccharide Which of the following structures is associated with Gram-positive bacteria? a. Teichoic acid b. Periplasmic space c. Peptidoglycan d. Lipopolysaccharide What term is used to describe bacterial cells that are spherical in shape? a. Bacillus b. Coccus c. Spirillum d. Vibrio Which of the following is a function of a capsule? a. Promotes phagocytosis b. Protects cells from bursting c. Allows bacteria to adhere to surfaces and each other d. Regulates movement of water into and out of the bacterial cell Which of the following is a function of peptidoglycan? a. Promotes phagocytosis b. Protects cells from bursting c. Allows bacteria to adhere to surfaces and each other d. Regulates movement of substances into and out of the bacterial cell Which of the following is a function of the cell membrane? a. Promotes phagocytosis b. Protects cells from bursting c. Allows bacteria to adhere to surfaces and each other d. Regulates movement of substances into and out of the bacterial cell Which of the following statements about pili is false? a. They contain adhesins, which allow the bacteria to adhere to receptors on cells or tissues. b. They promote chemotaxis. c. Attachment pili increase pathogenicity of Neisseria gonorrhoeae. d. They are involved in conjugation. Which of the following statements about endospores is false? a. They are resistant to heat and drying. b. Clostridium are capable of producing endospores. c. They are used for reproduction. d. Endospore formation begins with the building of the endospore septum. Which of the following statements is true about chemotaxis? a. Movement towards a nutrient is an example of negative chemotaxis. b. Movement towards light is an example of positive chemotaxis. c. Flagella facilitate chemotaxis. d. Pili facilitate chemotaxis. ___________ are intracellular pathogens that require a host cell to replicate. a. Fungi b. Protists c. Helminthes d. Viruses Which of the following statements is true about reverse transcriptase? a. It is associated with the Adenoviridae family. b. It is associated with the Retroviridae family. c. Double-stranded RNA viruses require it. d. It replicates RNA from DNA. What is the difference between a naked virus and an enveloped virus? a. A naked virus contains a nucleocapsid, but the enveloped virus does not. b. An enveloped virus contains a nucleocapsid, but the naked virus does not. c. A naked virus contains an external membrane, but the enveloped virus does not. d. An enveloped virus contains an external membrane, but the naked virus does not. Which of the following is not a viral group? a. Positive sense DNA virus b. Double-stranded DNA virus c. Single-stranded DNA virus d. Double-stranded RNA virus Which viral family is composed of (-) sense single-stranded RNA with an envelope and causes the flu? a. Flaviviridae b. Orthomyxoviridae c. Retroviridae d. Adenoviridae Which type of infectious agent can be multicellular or single-celled and can reproduce both sexually and asexually? a. Fungi b. Viruses c. Helminthes d. Bacteria Histoplasma are dimorphic fungi. What of the following statements is true about Histoplasma? a. They can reproduce asexually and sexually. b. They can grow in a yeast-like form or as a filamentous mycelium. c. They cannot form hyphae. d. They only reproduce sexually. Which of the following statements is false about hypha? a. They are used to form long filaments of fungi. b. Fungi can regrow from a single hyphal cell. c. A yeast cell is called a hypha. d. They can contain multiple nuclei. Which phylum of fungi contains Rhizopus, which can reproduce both sexually and asexually? a. Ascomycota b. Basidiomycota c. Deuteromycota d. Zygomycota Which of the following fungi are included in the Basidomycota phylum? a. Saccharomyces b. Black bread mold c. Mushrooms d. Penicillium All of the following phyla of fungi have a sexual stage, except: a. Ascomycota b. Basidiomycota c. Deuteromycota d. Zygomycota Which of the following organisms are multicellular animals that contain rudimentary organ systems? a. Protozoa b. Yeast c. Helminths d. Algae Which of the following organisms are unicellular, contain organelles, and can cause vector-borne diseases, including sleeping sickness? a. Protozoa b. Slime molds c. Helminths d. Algae Module 2 Practice Test Questions Which of the following refers to the time between initial infection and symptom onset? a. Incubation period b. Invasive phase c. Prodromal phase d. Convalescent period A person has been ill with a bad cold. She is now feeling better, but is still not 100%. What disease stage or period is she currently in? a. Incubation period b. Invasive phase c. Prodromal phase d. Convalescent period Which statement best describes the relationship between a parasitic microorganism and a human host? a. The microorganism and human both benefit equally from the relationship. b. The human benefits slightly more than the microorganism. c. The microorganism benefits, while the human suffers. d. The microorganism benefits from the relationship, while the human is neither helped nor harmed by it. Microorganism X lives inside Human Y, where it has everything it needs to thrive. In exchange, Microorganism X makes vitamins for Human Y. Which of the following best describes this type of relationship? a. Commensalism b. Parasitism c. Mutualism d. Antagonism What is the primary reservoir for the pathogen that causes tetanus? a. Contaminated food b. Soil c. Contaminated water d. Infected animals What is the primary reservoir for the pathogen that causes histoplasmosis? a. Deer ticks b. Contaminated water c. Cat scratches d. Aerosols of dried feces Module 3 Practice Test Questions What is an example of a physical barrier that helps to protect the body from infectious agents? a. Sweat b. Lysozyme c. Mucosa d. defensins Which is an example of a specific defense: a. Production of antibodies by B cells b. Engulfing of bacteria by macrophages c. Creation of a membrane attack complex by the complement system d. Induction of fever by cytokines Which cells will take longer to respond to a pathogen, but will be able to be part of an adaptive response to the pathogen? a. Neutrophils b. Eosinophils c. Natural killer cells d. T cells Which cells are a type of lymphocyte? a. Red blood cells (erythrocytes) b. Macrophages c. B cells d. Neutrophils Which cell type is responsible for producing antibodies? a. Cytotoxic T cells b. Helper T cells c. Macrophages d. B cells How might an individual naturally acquire adaptive immunity to influenza? a. Receive an influenza vaccination b. Receive antibodies purified from an influenza patient c. Become infected with the flu and generate memory cells specific for influenza d. Become infected with rhinovirus How might an individual artificially acquire passive immunity to influenza? a. Receive an influenza vaccination b. Receive antibodies purified from an influenza patient c. Become infected with the flu and generate memory cells specific for influenza d. Become infected with rhinovirus Which antibody isotype is produced first during both primary and secondary immune responses? a. IgA b. IgD c. IgM d. IgE Which cells respond very quickly to tissue injury and protect mucous membranes and blood against infection? a. Basophils b. T cells c. Neutrophils d. B cells What is a type of molecule capable of helping in intercellular communication and in activating leukocytes? a. Mast b. Fever ion c. Monocyte d. Cytokine Which cells can both ingest pathogens and activate cells of the adapative immune system? a. Red blood cells (erythrocytes) b. Macrophages c. Mast cells d. Eosinophils Which antibody isotype is primarily found guarding mucosal surfaces? a. IgA b. IgD c. IgM d. IgE Patients suffering from respiratory allergies typically have high levels of which type of antibody? a. IgA b. IgD c. IgM d. IgE Of the four types of hypersensitivity, which type involves antibodies but does not specifically rely on immune complex formation? a. Type I b. Type II c. Type III d. Type IV The exact cause of rheumatoid arthritis is unknown. We do know that it involves the following: a. An allergic response b. Attack of the immune system on the body’s own cells c. Excessive IgE in the body d. High levels of parasites in the body Module 4 Practice Test Questions What is the mode of action of sulfonamides? a) Inhibition of cell wall synthesis b) Inhibition of protein synthesis c) Prevention of folic acid synthesis d) Prevention of niacin synthesis How does erythromycin, the most common macrolide, prevent bacterial growth? a) Inhibition of protein synthesis. b) Inhibition of B6 synthesis. c) Inhibition of cell wall synthesis. d) Inhibition of nucleic acid synthesis. How do aminoglycosides exert their action? a) Inhibition of protein synthesis. b) Inhibition of B6 synthesis. c) Inhibition of cell wall synthesis. d) Inhibition of nucleic acid synthesis. How do quinolones and rifampin exert their action? a) Inhibition of protein synthesis. b) Inhibition of folic acid synthesis. c) Prevention of cell wall synthesis. d) Inhibition of nucleic acid synthesis. The anti-helminthic agent niclosamide interferes with which of the following? a) Carbohydrate metabolism b) RNA polymerase c) Protein synthesis d) Calcium uptake The antiviral drug azidothymidine (AZT), which is used to treat patients infected with HIV, does which of the following? a) Prevents reverse transcriptase b) Stimulates the patient’s immune system c) Destroys the viral membrane d) Destroys the viral capsid Penicillins could be inactivated if a bacterial strain acquired which of the following mechanism of resistance? a) Betalactamase enzyme b) Alteration of targets c) Alteration of membrane permeability d) Alteration of metabolic pathway Which mechanism of resistance can be directly caused by changes in cell membrane proteins? a. Alteration of targets b. Alteration of membrane permeability c. Development of enzymes d. Alteration of a metabolic pathway Resistance to erythromycin can be caused by which mechanism of resistance? a) Development of an enzyme b) Alteration of an enzyme c) Alteration of membrane permeability d) Alteration of a target A college student is prescribed antibiotics for a respiratory infection. The clinician emphasizes that she must take the drugs for the full ten days. Why? a) Many bacteria take quite a while to die b) It takes several days for the body to become used to the antibiotic c) Drugs are expensive and should not go to waste d) Bacteria that are not killed by the antibiotic can become resistant Streptomycin and penicillin might be prescribed together to treat an infection. This is because streptomycin destroys the cell wall, allowing penicillin to be better absorbed. This dual-action is an example of which of the following? a. Antagonism b. Synergism c. Quorum sensing d. Cross-resistance What is the target of the drug tetracyline? a. Carbohydrate metabolism b. Nucleic acid synthesis c. Ribosomal subunits d. Protein synthesis Which mechanism would NOT result in resistance to chloramphenicols? a. Alteration of the metabolic pathway b. Mutation of ribosomal subunits c. Reduced membrane permeability d. Changes in chloramphenicol acetyltransferase Module 5 Practice Test Questions Frank buys milk each Saturday morning from his neighbor's cow Bessie. What method should be used for controlling microbial growth? a. Irradiation b. Pasteurization c. Filtration d. Autoclaving What is the mode of action for the antimicrobial function of detergents? a. Disrupting cells membranes b. Inhibiting nucleic acid synthesis c. Inhibiting protein synthesis d. Methylating DNA Bactericides reduce microbial growth by: a. Deactivating viruses b. Inhibiting viral replication c. Killing bacteria d. Destroying fungi Virucides reduce microbial growth by: a. Deactivating viruses b. Inhibiting viral replication c. Killing bacteria d. Destroying fungi This substance, which acts by denaturing proteins, is commonly used to disinfect skin. a. Alcohol b. Heavy metal c. Formaldehyde d. Dye Which of the following is routinely used to disinfect utensils in restaurants? a. Pasteurization b. Sterilization c. Sanitization d. Filtration Which of the following lowers pH and is consequently used to preserve food? a. Alcohols b. Acids c. Oxidizing agents d. Halogens A microbiologist’s child drops a beloved toy into a pile of cow dung. If she had every resource at her disposal, which method could she use to destroy all the microorganisms and viruses on her child’s toy? a. Sterilization b. Ultraviolet light c. Pasteurization d. Alcohol disinfection Which of the following is used to ensure antibiotics are sterile? a. Ultraviolet light b. Pasteurization c. Moist heat d. Filtration A woman falls while hiking and gets a puncture wound on her leg. She visits the First Aid station for assistance. Which of the following compounds can break disulfide bonds and would be a good choice to treat her injury? a. Formaldehyde b. Oxidizing agent c. Detergent d. Silver nitrite Microbial growth on spices such as cinnamon and nutmeg can be controlled through which of the following methods? a. Irradiation b. Filtration c. Moist heat d. Pasteurization Alkylating agents act against microbes through which mechanism? a. Raising pH b. Denature proteins c. Disrupt nucleic acids d. All of the above Endospores can be most effectively destroyed through which of the following methods? a. Irradiation b. Autoclave (moist heat) c. Pasteurization d. Filtration Which method is commonly used in lab animal rooms to limit the number of microorganisms present in the air? a. Filtration b. Ultraviolet light c. Moist heat d. Very low temperatures Alcohol is an effective antimicrobial agent because it does which of the following? a. Denatures proteins b. Disrupts nucleic acids c. Dissolves membranes d. Both A and C are correct

Answer 1

1.which of the following microorganisms lack of mitochondria?

a. Fungi b. Bacteria c. Parasites d. Protists

Answer: The main differences between Prokaryotes and eukaryotes includes the presence of mitochondria and cell wall, chloroplasts, and chromosomal DNA. Eukaryotic cells contain membrane-bound organelles such as the nucleus, but prokaryotic cells do not.so, the answer is option b Bacteria.because bacteria belong to prokaryotes, it does not have mitochondria.but fungi, parasites, protists are Eukaryotes they have membrane-bound structures .so they have mitochondria.

2. Which bacteria have cell walls that are approximately 10-20% peptidoglycan?

a. Gram-positive b. Gram-negative c. Acid-fast d. Wall-deficient

Answer: Peptidoglycan is a mesh-like layer outside the plasma membrane of the bacteria which consists of sugar and amino acids which forms cell wall. the peptidoglycan layer is comparatively thicker in gram-positive bacteria than in gram-negative bacteria. The presence of high levels of peptidoglycan is the main determinant of the gram-positive bacteria. peptidoglycan forms around 90% of the dry weight of gram-positive and only 10% of the gram-negative strains. acid-fast strain wall consists of peptidoglycan and glycolipids. wall deficient not have peptidoglycan.so in the given option the answer is option b Gram-negative.

3. Which bacteria are difficult to Gram stain?

a. Gram-positive b. Gram-negative c. Acid-fast d. Wall-deficient

Answer: acid-fast bacteria cannot be /poorly stained by gram stain because of the high lipid content in their cell wall.acid-fast strains are stained by acid-fast staining eg: mycobacteria. option a,b,d can be stained by gram stain method easily compared to acid-fast strain. so the answer is option c Acid fast.

4. Which of the following types of bacteria are slow-growing, due to the high lipid content of their cell walls?

a Gram-positive b Gram-negative c. Acid-fast d. Wall-deficient

Answer: Acid-fast bacterias have high lipid contents in their cell wall, so they are slow-growing. option a,b,d not have high or no lipid contents in their cell wall compared to acid-fast bacterias.

so the answer is option c Acid-fast.

5. Which of the following types of bacteria have strong cellular membranes that contain sterols?

a Gram-positive b. Gram-negative c. Acid-fast d. Wall-deficient

Answer: Mycoplasma is an example of bacteria that have no cell wall. this type of bacterias acquire cholesterol from the environment and form sterols which helps to build their cytoplasmic membranes.these are tough membranes and that are more resistant to rupture and not effective with antibiotic treatment. option a,b,c bacterias do not contain sterol in their cell wall.so the answer is option d wall deficient.

6. Which of the following types of bacteria have both a cell membrane and an outer membrane?

a. Gram-positive b. Gram-negative c. Acid-fast d. Wall-deficient

Answer: gram-negative bacteria have a thin peptidoglycan cell wall and which itself surrounded by an outer membrane that contains a lipopolysaccharide. option a,c,d do not have an outer membrane.so the answer is option b gram-negative.

7. Which of the following is an endotoxin, which can cause fever and inflammation, and is associated with Gram-negative bacteria?

a. Teichoic acid b. Periplasmic space c. Peptidoglycan d. Lipopolysaccharide

Answer: Lipopolysaccharide(LPS) consists of lipid and a polysaccharide composed of O-antigen , joined by a covalent bond also known as lipoglycans and endotoxins. Lipid A portion of LPS causes endotoxin activity. actually it directly makes a harm to tissues but the immune cells of humans and animals see it as an indicator of the presence of the bacteria, causes fever and inflammation.so the answer is option d Lipopolysaccharide.