Biology Competitive Exam 2021-2022
62 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Eubacteria that lack cell walls and do not synthesize the precursors of peptidoglycan are called

  • Gram-negative bacteria
  • Mycoplasmas (correct)
  • Viruses
  • Bacilli
  • Serovar

    • Most microorganisms pathogenic for humans grow best in the laboratory when cultures are incubated at

  • 15-20°C
  • 30-37°C (correct)
  • 20-30°C
  • 50-55°C
  • 38-50°C

    • Which of the following specimens does not usually contain anaerobes?

  • Cerebrospinal fluid from a patient with meningitis
  • Throat swab from a patient with a sore throat (correct)
  • Expectorated sputum from a patient with community-acquired pneumonia
  • Aspiration from an infected maxillary sinus

    • How many organisms must be present in a clean catch midstream urine sample to be considered indicative of an infection?

    <p>&gt; 10^5 CFU/mL</p> Signup and view all the answers

    Which type of direct specimen involves collecting fluid from the lower respiratory tract?

    <p>Expectorated sputum</p> Signup and view all the answers

    Which of the following represents a level of laboratory safety concerning biological hazards?

    <p>Level 1</p> Signup and view all the answers

    Which method is not typically used to diagnose infections in the genital tract?

    <p>Cell culture using cycloheximide containing McCos cells</p> Signup and view all the answers

    What is the primary use of charcoal in buffered charcoal yeast extract agar?

    <p>Act as a detoxifying agent</p> Signup and view all the answers

    Which test is most readily used to confirm M. pneumoniae infection in the laboratory?

    <p>PCR</p> Signup and view all the answers

    Which characteristic is essential in a nontreponemal serological test?

    <p>Measuring antibodies against lipids</p> Signup and view all the answers

    For which purpose is enzyme immunoassay (EIA) performed on genital tract specimens?

    <p>Detecting bacterial antigens</p> Signup and view all the answers

    What is a definitive method for identifying an anaerobic bacterium?

    <p>Cell wall fatty acid analysis using gas liquid chromatography</p> Signup and view all the answers

    Which test differentiates M. catarrhalis from saprophytic neisseriae in respiratory samples?

    <p>Biochemical tests</p> Signup and view all the answers

    Which test is useful for monitoring antibiotic treatment of primary or secondary syphilis?

    <p>Nontreponemal serological tests</p> Signup and view all the answers

    The microorganism that could use CO2 as a carbon source and inorganic chemical compounds as an energy and electron source is:

    <p>Chemolithoautotroph</p> Signup and view all the answers

    The compound that lacks the presence of phosphates in the structure of a bacterial Gram-positive cell wall is:

    <p>Tichuronic acid</p> Signup and view all the answers

    The microorganism that has no ability to synthesize a growth factor is:

    <p>Auxoheterotrophic</p> Signup and view all the answers

    The swarming of Proteus bacteria is inhibited if the concentration of agar is:

    <p>1.5%</p> Signup and view all the answers

    Nitrosomonas is:

    <p>Chemolithoautotroph</p> Signup and view all the answers

    Which one of the following is most responsible for the nature of the lesion on the foot caused by Staphylococcus aureus?

    <p>Superantigen toxin (StaphSAg)</p> Signup and view all the answers

    The blood culture was negative. What is the best explanation for this?

    <p>This is typical in staphylococcal TSS. Only the StaphSAg needs to circulate</p> Signup and view all the answers

    Which of the following is present in prokaryotes but not eukaryotes?

    <p>simultaneous transcription and translation</p> Signup and view all the answers

    The nitrogen bases in DNA are bonded to the:

    <p>deoxyribose</p> Signup and view all the answers

    Which of the following mediums is selective for Salmonella?

    <p>Hektoen Enteric Agar</p> Signup and view all the answers

    Which hypersensitivity reaction is predominantly involving IgE?

    <p>Type I</p> Signup and view all the answers

    Cytotoxic T cells kill their targets via which mechanisms?

    <p>Perforin and Granzyme B</p> Signup and view all the answers

    Pattern recognition molecules can distinguish:

    <p>self from pathogen</p> Signup and view all the answers

    Which of the following inhibits DNA gyrase?

    <p>Ciprofloxacin</p> Signup and view all the answers

    Which of the following antimicrobial drugs is synthetic?

    <p>sulfanilamide</p> Signup and view all the answers

    Which clinical situation would be appropriate for treatment with a narrow-spectrum antimicrobial drug?

    <p>treatment of strep throat caused by culture identified Streptococcus pyogenes</p> Signup and view all the answers

    Which of the following is not a type of β-lactam antimicrobial?

    <p>glycopeptides</p> Signup and view all the answers

    Which of the following resistance mechanisms describes the function of β-lactamase?

    <p>target mimicry</p> Signup and view all the answers

    The etiology of the sore throat would have been best determined by:

    <p>Throat culture</p> Signup and view all the answers

    Virulence means:

    <p>A term which presumes pathogenicity, but allows expression of degrees from low to extremely high</p> Signup and view all the answers

    What laboratory test would be most likely to confirm the diagnosis of Lyme disease?

    <p>Borrelia burgdorferi immunoassay plus immunoblot</p> Signup and view all the answers

    An F-pilus is essential for:

    <p>Plasmid transfer by conjugation</p> Signup and view all the answers

    Which of the following statements about gene expression is false?

    <p>Translation begins at a site called a promoter</p> Signup and view all the answers

    Which of the following is NOT characteristic of eukaryotic gene expression?

    <p>The mRNA is often polycistronic</p> Signup and view all the answers

    The presence of which of the following is NOT typically used to determine the etiology of a sore throat?

    <p>DNA sequencing</p> Signup and view all the answers

    Which diagnostic method is NOT typically associated with Lyme disease?

    <p>Throat culture</p> Signup and view all the answers

    Which of these is a type of Anthrax?

    <p>Cutaneous Anthrax</p> Signup and view all the answers

    On which of these media can Salmonella grow?

    <p>Desoxycholate agar</p> Signup and view all the answers

    Salmonella can ferment which of the following?

    <p>Mannitol</p> Signup and view all the answers

    Which of the following are antigens found in Enterobacteriaceae?

    <p>All of above</p> Signup and view all the answers

    Which toxins are secreted by E. coli?

    <p>Heat stable toxin</p> Signup and view all the answers

    Which antigens does Klebsiella have?

    <p>O antigen</p> Signup and view all the answers

    Lactobacillus ferments sugars to produce which of the following?

    <p>Lactic acid</p> Signup and view all the answers

    Which of the following antibiotics have an extended spectrum?

    <p>Aminoglycosides</p> Signup and view all the answers

    What patterns of disease outbreaks in communities exist?

    <p>Sporadic Disease</p> Signup and view all the answers

    What is the indicator used in the phenylalanine deamination test?

    <p>Ferric Chloride</p> Signup and view all the answers

    How is antibacterial susceptibility determined?

    <p>Disk diffusion</p> Signup and view all the answers

    Which phenotypic trait is associated with a systemic fungal pathogen?

    <p>Dimorphic shape</p> Signup and view all the answers

    Which fungal pathogen causes Tinea corporis?

    <p>Trichophyton rubrum</p> Signup and view all the answers

    How saturated with oxygen is the hemoglobin in blood leaving the lungs?

    <p>98-99%</p> Signup and view all the answers

    Which type of bacterial enzyme does not need water for reactions?

    <p>Lyases</p> Signup and view all the answers

    What is an important nutrient for bacterial teichoic acid?

    <p>PO4</p> Signup and view all the answers

    Which bacterial group cannot grow at temperatures below 55°C?

    <p>Thermophiles</p> Signup and view all the answers

    Which metabolic pathway is used by bacteria but not by eukaryotes?

    <p>Entner-Doudoroff</p> Signup and view all the answers

    Which of the following are storage inclusions in bacteria?

    <p>Polyhydroxyalkonates</p> Signup and view all the answers

    All of the following are true regarding penicillins EXCEPT

    <p>Penicillins don’t require dosage adjustment in renal failure.</p> Signup and view all the answers

    Which of the following antibiotics does NOT inhibit nucleic acid synthesis?

    <p>Chloramphenicol</p> Signup and view all the answers

    Which of the following antibiotics functions as a protein synthesis inhibitor?

    <p>Tetracycline</p> Signup and view all the answers

    Study Notes

    Microbiology Examination Questions

    • Competition Examination 2021-2022
      • Questions 1-5: Multiple choice questions on various microbiology topics, including bacterial growth, metabolism, and identification.

    Microbiology Topics

    • Serology
      • Using complement fixation, cell culture, direct fluorescent antibody testing, nucleic acid amplification methods, and enzyme immunoassays to diagnose infections.
    • Lyme Disease
      • Laboratory diagnosis of Lyme disease involves Borrelia burgdorferi immunoassay, immunoblot, and PCR of CSF.
    • Spore Formation
      • Stages of spore formation: vegetative cell, sporulation, and germination.
    • F-pilus
      • Essential for DNA transformation, chromosome transfer by conjugation, and plasmid transfer by conjugation.
    • Gene Expression
      • More than one RNA polymerase can transcribe a specific gene at a given time; translation begins at a site called a promoter.
    • Eukaryotic Gene Expression
      • Characteristics: 5' cap added to mRNA, poly A tail added to 3' end of mRNA, introns removed, and mRNA is often polycistronic.

    Biology Exam

    • Multiple Choice
      • Prokaryotes lack spliceosomes; DNA is bonded to deoxyribose.
    • Short Answer
      • Compare conjugation, transformation, and transduction; differences between direct and indirect tests; selective mediums for Salmonella.

    Additional Questions

    • Microbial Activity
      • Determining microbial activity level involves measuring factors such as growth rate, metabolism, and enzyme activity.
    • Carbon Cycle
      • Differences between carbon cycle in land and microorganisms: land-based carbon cycle involves decomposition, while microorganisms use carbon dioxide and release oxygen.

    Q13-14

    • Antimicrobial Drugs
      • Inhibit DNA gyrase, such as Ciprofloxacin; sulfanilamide is a synthetic antimicrobial drug; narrow-spectrum antimicrobial drugs for specific infections.
    • Antimicrobial Resistance
      • Mechanisms: target mimicry, β-lactamase, and others.

    Questions

    • Coagulase and Fibrinolysin
      • Differences between coagulase and fibrinolysin in protection of pathogenic bacteria.
    • Media
      • Purpose of using EMB, CLED, Deoxycholate citrate agar, Bismuth sulphate, and Thiosulfate-citrate-bile-sucrose (TCBS) media.
    • Cholera
      • Pathogenesis of cholera diarrhea involves first complex compound, which is a toxin produced by Vibrio cholerae.

    Choose the Suitable Answer

    • Types of Anthrax
      • Cutaneous anthrax, pulmonary anthrax, and intestinal anthrax.
    • Salmonella
      • Grows on Desoxycholate agar, Xylose-lysine desoxycholate agar, and Blood agar; ferments glucose and mannitol.
    • E. coli
      • Secrete heat labile and heat stable toxins.
    • Lactobacillus
      • Ferments sugars to produce lactic acid.

    Answer All

    • Metabolic Pathways
      • Regulation of metabolic pathways involves feedback inhibition, allosteric control, and substrate availability.
    • Extracellular Proteins
      • Secreted from cytoplasmic membrane: lipopolysaccharides, capsules, and proteins.

    Q4 - Fill the Blank

    • Aminoglycosides
      • Have an extended spectrum, such as gentamicin.
    • Phenylanine Deamination
      • Indicator used in phenylanine deamination test.
    • Antibacterial Susceptibility
      • Determined through disc diffusion test.
    • Streptococcal Group
      • Can hemolyze blood completely.
    • Polymyxin
      • Used to treat gram-negative infections.

    Example for Each

    • Fungal Pathogens
      • Histoplasma capsulatum has a dimorphic shape; Trichophyton rubrum causes Tinea corporis; Candida albicans has adhesins as a virulence factor; Aspergillus fumigatus is a systemic fungus; fluconazole is an antifungal drug.

    True or False

    • Hemoglobin
      • True: Hemoglobin in blood leaving the lungs is about 98-99% saturated with oxygen.
    • Hemopoiesis
      • True: Sites of hemopoiesis in infants occur in the yolk sac.
    • Aplastic Anemia
      • True: Causes of aplastic anemia include toxic substances, such as pesticides, arsenic, and benzene.
    • Iron Storage
      • True: Some iron is stored in the phagocytic as ferritin and hemosiderin.
    • Hypoxia
      • True: Hypoxia occurs in patients when they ascend to high altitude.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz assesses knowledge of biology topics, including microbial metabolism and cellular structure. Questions cover various aspects of biology, with equal weightage and 20 points each.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser