Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
BIO171 Microbio exam questions with answers already graded a+
Typology: Exams
1 / 32
1. A virus is classified as a microbe.True. Although viruses are not living and as such are not considered microorganisms, they can, however, be classified as microbes, a more general term that includes microorganisms and viruses. 2. True or False: The smallest biological unit of life is the molecule.False. The smallest biological unit of life is the cell. 3. What are the 4 main types of macromolecules found in cells?Proteins, Lipids, Nucleic acids and Polysaccharide 1. Proteins are formed from various combinations of of which there are known forms.Amino acids, 20 2. How many amino acids are classified as being essential amino acids? 9
A. Only restricts movement of materials into the cell B. Is often a bilayer comprised of lipids C. Cannot prevent essential nutrients from escaping D. Contains hydrophobic tails pointing inward
2. Carbon, Hydrogen and Oxygen atoms come together to form what primary macromolecule? Give an example.Polysaccharides. Glucose, sucrose and cellulose are all acceptable answers. True of False: The genetic material within a prokaryotic cell is contained within a membrane- enclosed region.False. Only eukaryotic cells contain its genetic material within a nucleus True or False: Prokaryotic cells can be subdivided into Bacteria and Archaea.True Describe the 4 basic bacterial morphologies.Coccus (round/spherical), bacillus (rod), vibrio (curved rod) or spirillum (spiral/corkscrew). True or False: Archaea is noted for its ability to survive under harsh conditions.True. Archaea can often be found in harsh conditions such as high salt levels, high acid conditions, high temperatures and even oxygen-poor conditions. 1. Animalia, Plantae, Fungi and Protista are all classification under what type of organism?B A. Bacteria B. Eukarya C. Archaea D. Virus 2. All multicellular microorganisms classified as Animalia are autotropic.False—they are heterotropic. 3. Microorganisms classified as obtain most of their energy by converting light energy into chemical energy.Plantae
contain chitin? Select all that apply.ACD A. Mushrooms B. Bacteria C. Yeast D. Molds
2. True or False: A defining characteristic of Protista is the inability of colonies to form tissue layers.True. 1. Cell walls are found in which of the following (select all that apply):A, B, C, E A. Plants B. Fungi C. Bacteria D. Mammalian cells E. Algae 2. The function of the ribosome is (select all that apply):B A. Lipid synthesis B. Protein synthesis C. To produce energy (ATP) D. Protein modification and distribution E. Waste disposal via hydrolytic enzymes 1. True or False: Metabolism is a controlled set of biochemical reactions that occur in living organisms in order to maintain life.True.
2. True or False: Enzymes are polysaccharides that catalyze chemical reactions.False. Enzymes are proteins that catalyze chemical reactions. 3. What are usually metal ions known to assists enzyme during the catalysis reaction? Cofactors are usually metal ions and assist enzyme during the catalysis reaction. 1. Define anabolism.Anabolism is the process of building up or biosynthesis of macromolecules from small molecular units into much larger complexes. 2. In order to convert proteins into amino acids which metabolic process would be active? Catabolism would be active as proteins are made up of amino acids. Therefore the process described (proteins into amino acids) is the breakdown, or catabolism of protein. 1. Describe the energy transfer process relative to both ATP and ADP.ATP has the energy (phosphate group) to donate while ADP can accept energy in the form of a phosphate group. Thus, ATP can be reduced (ATP →ADP + Pi) while ADP can be built into ATP (ADP + Pi →ATP).
2. For the catabolism of proteins and lipids, which of the following enzymes are used? Select all that apply.B and D. Proteases breakdown proteins while lipases breakdown lipids. A. Ligases B. Proteases C. Transferases D. Lipases 3. True or False. The β-oxidation pathway catabolizes the fatty acid chains of lipids.True 1. True or False. Plants, algae and bacteria all contain chloroplasts.False. Chloroplasts are specific to algae and plants only. 2. The process of carbon fixation begins with which of the following reactants: select all that apply.A, C, D, and E. Carbon fixation uses the ATP/NADPH produced during light reactions to convert CO2 and H2O into useful sources of energy (carbohydrates). A. ATP B. Glyceraldehyde-3-phosphate C. CO 2 D. NADPH E. H 2 O
stage in photosynthesis—dark reactions do not actually require darkness in order to occur.
3C 3. A—^ + B → A + B—^ Oxioreductaces 4B 4. Ab + C → A + Cb Transferases
B. Condenser C. Iris diaphragm D. Eye piece C. The iris controls the amount of light that passes through the sample and into the objective lens. Thus, it can be adjusted (opened or closed) to alter the amount of light.
Fluorescenc e Confocal This type of microscope is best suited for visualizing GFP, RFP and YFP proteins.Fluorescence
2. This type of microscope can provide detailed images of live cells without staining.Phase-Contrast 3. This type of microscope is used to greatly increase the contrast between samples and background by reflecting light off of the specimen.Dark Field 4. This type of microscope is capable of capturing images in multiple focal planes, rendering a specimen in 3DConfocal 1. Gram-Positive cells appear in color due to a peptidoglycan layer in the cell wall.Purple; Thick 2. Gram-Negative cells appear in color due to a peptidoglycan layer in the cell wall.Pink; Thin
in the outer membrane.True.
2. True or False: If you wish to study the motility of an organism you cannot heat fix, but you can chemically fix the specimen.False. Both heat and chemical fixation strategies will kill the cell, making motility observations impossible. 1. You want to observe the size and shape of a cell. What is the easiest staining technique that you could perform? Name at least one dye you would use during this process.Simple stain. You could use any of the following: methylene blue, crystal violet, safranin or fuschin. 2. You suspect a patient may have TB. Once a sample has been obtained it is sent off to the lab for an acid-fast stain. If the patient were infected with TB, describe what you would expect to see on the stained slide.You would expect to see red cells (TB+) on a blue background (TB negative). 3. True or False: A Giemsa stain can be used to determine the presence of pathogenic bacteria.True. Pathogenic bacteria would appear pink while non-pathogenic bacteria would appear purple. 1. True or False: Differential media is best suited for distinguishing between two similar species of bacteria.True. Growth media does not contain restrictive factors, while selective media is best used to encourage the growth of one microbe while simultaneously discouraging the growth of the other. Since two similar species of microbes are being studied they must be differentiated under similar but just slightly different conditions (differential media). 2. A researcher is asked to determine if a sample contains Neisseria meningitides. Knowing Neisseria meningitides is slow growing and other foreign microbes may also be present in the culture, which type of media would be best suited:C A. Growth media B. Differential media C. Selective media D. Selective and Differential media
1. True or False: LB agar is classified as a selective, non-differential media.False. LB agar is the
most basic type of agar and like LB media supports the growth of virtually all microbes without restriction.
2. What is agar used for in microbiology?Agar is used to create a solid, smooth surface on which microbes can grow.
1. What is the Gram status (Positive or Negative) of microbes growing on Eosin Methylene Blue (EMB) agar plates?Gram-Negative. EMB plates specifically restrict the growth of Gram- Positive bacteria. 2. Mannitol salt agar will turn what color in the presence of the pathogenic strain Staphylococcus aureus?Yellow. Pathogenic Staph aureus will turn the agar from red to yellow. 1. What is the process of spreading a bacterial culture onto a petri dish?Plating. 2. In order to visual individual colonies of bacteria would you culture your sample in a liquid media or on a solid (agar) media? Why?Solid (agar) media. The primary advantage is that cells are held into place. When grown in a nutrient broth, bacterial cells can multiply but are free to move around in solution. When grown on agar within a petri dish the fixed in such as way as to form colonies. 3. True or False? The visualization of colonies on a petri dish represents bacterial cells that have often multiplied a million times over.True. To form a bacterial colony the initial cell must have multiplied many times over, often greater than a million, in order for the naked eye to resolve it. 1. True or False. The purpose of a quadrant streak is to produce individual colonies of a bacterial population.True. The purpose of the quadrant streak is to generate individual colonies such that a single (pure) bacterial sample can be isolated. 2. A dilution gradient is formed when carrying out what generalize plating strategy? A quadrant (aka phase-dilution) streak. The resulting gradient should always contain within it the growth of individual colonies. 3. In what phase of a dilution streak would you expect to find the highest concentration of bacteria, P2 or P4?P2 (Phase 2) would contain a higher concentration of bacteria than Phase 4 (P4). The phases rank (from highest to lowest), P1 > P2 > P3 > P4. 1. True or False. When performing a dilution streak a new (or sterilized) loop must be used for each phase.True. Failure to do so would prevent the establishment of a dilution gradient, as the same bacterial concentration would be spread across both phase regions.
phase dilution streak?A researcher may either (1) opt to perform only a 3-phase dilution streak or (2) pass the loop through the previous phase multiple times (as opposed to only once).
3. True or False. To restrict the growth of a pathogenic microbe a researcher might decrease an incubator from 37°C to 25°C.True. Pathogenic strains of bacteria tend to grow faster than non- pathogenic strains at 37°C, so researchers may set incubators at 25°C to restrict its growth. When given an unknown bacterial sample the first step is to expand the current bacterial population. Which form of media best suites this need? Why? A. MSA agar B. LB media containing ampicillin and neomycin C. MacConkey agar D. Blood agar D. Blood agar. All other options (A, B and C) are all forms of selective media, meaning they may potentially inhibit the growth of the unknown sample. Although blood agar is considered a differential media, it is, most importantly, a non-selective media. Given the alternatives, this is the best option. 1. Define the concept of universal precautions.Universal precautions means any and all samples, whether known or unknown, are to be treated as potentially hazardous (or pathogenic) materials. 2. List at least 3 observations a researcher would be sure to note while assessing an unknown microbial sample A lab researcher would be certain to note:1. Size and shape2. Any observable motility3. Gram status (positive or negative)4. The presence of any chemical reactions5. Changes in color localized to the organism or the surrounding media6. Capture (or draw) images of any of the characteristics described above 1. While observing an unknown sample of limited amounts, a researcher must determine the following observations: (1) the presence of any motility and (2) its Gram status using the same sample—the liquid sample cannot be divided. Which would you determine first and why?You must determine motility before determining the Gram status. Motility requires a wet mount, while
Gram staining requires heat fixing the sample. If one were to begin with the Gram stain the heat fixation process would kill the organism, making any observations regarding motility impossible. The correct approach would be to place the liquid culture on a glass slide and determine its motility status. Next, the same liquid culture can be heat fixed and Gram stained.
2. A facultative anaerobe is a microorganism capable of growth under what conditions?A facultative anaerobe is capable of growth under aerobic (with oxygen) and anaerobic (without oxygen) conditions. 1. As Streptococcus is catalase negative would it thrive or die in the presence of peroxides? Why? Streptococcus would not survive in the presence of peroxides—it is unable to breakdown peroxides (catalase negative). Left unchecked, peroxides would damage the cellular integrity of Strep causing lysis/cell death. 2. Streptococcus is most often streaked onto C A. Chocolate agar B. EMB agar C. Blood agar D. Spirit Blue agar 3. True or False. The Lancefield groups are used to subdivide antigenic groups of gamma-hemolytic Streptococcus.False. The Lancefield groupings are used to subdivide beta-hemolytic Strep. 4. Greater than 90% of all human streptococcal infections belong to:C (group A) A. Group B B. Group D C. Group A D. Group C
5. Left untreated, strep throat can progress to , which displays hemolytic activity.C A. Strep. Pharyngitis; beta B. Strep. Septicemia; gamma C. Rheumatic fever; beta D. Strep. Pharyngitis; alpha 1. True or False. Under most circumstances, staphylococcus can be found in ~30% of human population where it remains pathogenic.False. While staphylococcus can be found in ~30% of the human population, it remains non-symptomatic. 2. When a bacterium neither harms nor benefits from the host from which it obtains nutrients, it is referred to as being .Commensal. 3. In order to differential screen staphylococcus species, agar plates should contain what additive? Bile salts. Staphylococcus species are capable of growth in the presence of bile salts. Folliculitis- DPus-filled lesions on skin or hair Scladed-skin syndrome- ERuptured pustules; treated with Penicillin Impetigo- AChildhood skin disease near mouth/nose Conjunctivitis- BInfection of thin, transparent scleral tissue Opthalmia Neonatorum- C infection occurs at time of birth
1. True or False. An acid-fast stain is best suited to identify Tuberculosis (as opposed to a Gram stain).True. TB shows a poor Gram stain and should be screened via an acid-fast stain. 2. True or False. Although TB must be inhaled and reside in the lung in order to cause infection, TB can also spread to the brain, spine and kidneys.True. TB can move systemically through the blood to infect other areas (brain, spine and kidney). However, when located outside of the lung, TB tends to be non-infectious. 1. True or False. Directly ingesting clostridium or its associated spores will not cause illness in adults.True. Only the direct ingestion of the pre-formed toxin will cause disease. 2. A 5-month-old child is given honey at breakfast and begins showing symptoms consistent with botulism. Would the child’s illness be classified as foodborne, infant or wound botulism?Infant. Although food (honey) is consumed, foodborne botulism is derived from improperly canned, low acid foods under anaerobic conditions. Such conditions were not described. No puncture wounds or injuries were described, ruling out wound. The child is suffering from infant botulism, as honey is a potential carrier of clostridium. The intestinal track of young children is still developing and clostridium is able to colonize and produce the associated toxin. 1. True or False. There are currently no cures for tetanus.True. Although the symptoms can be treated it is only to manage the discomfort not to cure. 2. Identify the medical condition characterized by robust carbohydrate fermentation under anaerobic conditions, swelling of the infected areas and fever.Gas gangrene. The key identifier here is the robust carbohydrate fermentation, which manifests as intense gas production and swelling— both trademark conditions of gas gangrene. 3. The alpha-toxin perfringolysin is associated with which medical condition caused by Gram-positive anaerobic bacteria?C. Gas gangrene. The bacterium that produces the alpha toxin perfringolysin is aptly named Clostridium perfringens. A. Tetanus B. Botulism C. Gas gangrene
D. Leprosy
1. You develop a fever, chills and pneumonia after recently using a warm midst vaporizer in an attempt to open your sinuses. What bacterial disease would a doctor suspect is causing your symptoms? Would the doctor suspect you contracted it from touching (potentially) contaminated doorknobs?Legionnaires. No—legionella cannot be spread simply by direct contact between people. Legionella can only be transmitted through droplets small enough to be breathed in. 2. True or False. Bubonic plague is often characterized by painfully swollen lymph nodes.True. 3. Which form of the plague is highly virulent? What does it target?Pneumonic plague is highly virulent and targets the respiratory (lungs) system. 2. Gonnorrhea is caused by: A A. Diplococcic bacteria B. Staphylococcus bacteria C. Gram-Negative spirochete
D. RNA virus
3. True or False. Chlamydia trachomatis can be grown on an agar plate alone.False. Chlyamdia is an obligate parasite and requires a host (viable cells) for its growth.
genetic material, similar to the nucleus of a eukaryotic cell.
1. The surrounds the capsid of some viruses.Envelope. 2. True or False. You would expect to see a viral envelope on a virus infecting a plant cell.False. The overwhelming majority of animal viruses are enveloped whereas the majority of plant or bacteria-infecting viruses are not.
5-Release: New virus particles are produced and leave the cell 4-Replication: the viral genome is the ‘blueprint’ to make copies of itself 1-Attachment: viral receptors bind to host proteins on the surface of the cell 2-Entry: the virus fuses with the host membrane and enters the cell 6-New infection: newly produced viruses that left the host cell now go on to infect new cells.
1. A virus that infects bacteria is called a and contains a -side polygon capsid.Bacteriophage; 20-sided 2. True or False. Structurally, bacteriophages are distinct from viruses that infect plant or animal cells.True. Bacteriophages are structurally distinct from viruses that infect plant and animals cells.
1. Which of the following cannot be spread via airborne particles:E A. Measles B. Mumps C. Rubella D. A and B E. None of the above 2. True or False. A patient infected with Rubella is considered infectious one week before and after the appearance of the trademark rash.True 3. Which of the following diseases does a linear, double-stranded DNA virus cause?E A. Measles B. Mumps C. Rubella D. B and C E. None of the above 4. What disease displays as a secondary characteristic swelling of the testes/ovaries and pancreas? Mumps. A patient infected with mumps (aka epidemic parotitis) has primary swelling in the parotid (salivary glands) located in the neck but also may have secondary swelling in the testes/ovaries and pancreas. 5. A patient diagnosed with German measles may additionally experience what disease? Select all that apply. BDA A. Impetigo B. Conjunctivitis
C. Rheumatic fever D. Influenza-like symptoms
1. Describe two ways chickenpox can be spread.Chickenpox is highly contagious and can be transmitted (1) through both air-borne droplets (sneezing/coughs) or via (2) direct contact with the blisters of an infected individual. 2. True or False. The development of shingles is most often seen in an older adult population (> 60 years old).True. The most common age for VZV reactivation and shingle diagnosis tends to occur in people around 60 years of age. 3. True or False. Unlike chickenpox, the blisters that appear with shingles are localized and limited to small areas.True. While chickenpox blisters often cover the entire body, the blisters associated with shingles are localized and limited to small areas. 4. A person who has neither previously had chickenpox nor been administered the VZV vaccine is exposed to someone with an active VZV (shingles) outbreak and becomes infected. Explain why (or why not) the person will only develop shingles.The infected individual will not develop shingles, but will develop chickenpox. Unvaccinated and unexposed individuals must first develop chickenpox, as shingles is the reactivation of the dormant VZV virus from the chickenpox infection. 1. While traveling abroad, should you be worried about coming into contact with either the Variola major or Variola minor viruses?No. Both viruses are variants of smallpox and were eradicated in 1977. You would not need to worry about coming into contact with the virus. 2. What small (~30nm) single-stranded, non-enveloped RNA virus causes temporary or permanent paralysis by infiltrating (infecting) motor neurons within the spinal cord, brain stem or motor cortex? Polio, also known as poliomyelitis. 3. Described the main underlining differences between the Salk and Sabin polio vaccine.The Salk vaccine contained an inactivated form of the virus and was injected while the Sabin vaccine contained a live attenuated (weakened) form of the virus and was administered orally. 4. Which subtype of Influenza is the most virulent?Influenza A