Bacterial Cell Growth Requirements Quiz
30 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

What is the term used to describe the time between bacterial cell divisions?

  • Division period
  • Generation time (correct)
  • Fission duration
  • Replication interval

    • Which of the following is NOT a physical factor that influences the rate of bacterial growth?

  • Carbon availability (correct)
  • Temperature
  • pH
  • Osmotic pressure

    • What is the optimum temperature range for the growth of psychrotrophs?

  • 20°C to 30°C (correct)
  • 50°C to 60°C
  • 0°C or below
  • 15°C or below

    • Which group of bacteria is most likely to cause disease or food spoilage in cold environments?

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

    Which of the following statements about mesophiles is correct?

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

    What is the minimum temperature at which thermophiles can grow?

    <p>45°C</p> Signup and view all the answers

    What is the primary role of water in the environment for microorganisms?

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

    What is the optimal water activity (aw) required for microbial growth and multiplication?

    <p>0.95</p> Signup and view all the answers

    How do freeze-dried foods prevent spoilage by microorganisms?

    <p>By decreasing the water activity</p> Signup and view all the answers

    What is the primary function of a solidifying agent in a culture medium?

    <p>To create a solid substrate for microbial growth</p> Signup and view all the answers

    What is the unique property of agar that allows it to be used as a solidifying agent in culture media?

    <p>It melts above 95°C and does not solidify until it reaches 40°C</p> Signup and view all the answers

    How does the water activity of foods relate to the rate of food spoilage?

    <p>Foods with high water activity spoil more rapidly</p> Signup and view all the answers

    Which of the following statements about thermophiles is correct?

    <p>They are a type of archaebacteria that thrive in volcanic and ocean vents.</p> Signup and view all the answers

    Which of the following statements about pH preferences of microorganisms is correct?

    <p>Neutrophiles, including most human pathogens, grow optimally at a pH range of 5.4 to 8.5.</p> Signup and view all the answers

    What is the primary reason for using buffers in microbial growth media?

    <p>To stabilize the pH of the media and prevent fluctuations.</p> Signup and view all the answers

    Which of the following statements about osmotic pressure and microbial growth is correct?

    <p>Hypertonic solutions remove water from cells, causing plasmolysis.</p> Signup and view all the answers

    Which of the following microorganisms is classified as an acidophile?

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

    Which of the following pH ranges is associated with alkaliphiles?

    <p>7.0 to 12.0 or higher</p> Signup and view all the answers

    What is the main characteristic of polysaccharides made by red algae?

    <p>They cannot be degraded by most bacteria</p> Signup and view all the answers

    What is the purpose of chemically defined media?

    <p>To provide a source of carbon and energy for chemoheterotrophs</p> Signup and view all the answers

    Which statement about anaerobic growth media is true?

    <p>They contain ingredients that chemically combine with oxygen</p> Signup and view all the answers

    What is the main advantage of complex media over chemically defined media?

    <p>Complex media are widely used for heterotrophic bacteria and fungi</p> Signup and view all the answers

    Which method is used to directly measure bacterial growth?

    <p>Viable membrane count</p> Signup and view all the answers

    If a dilution of 1/10,000 contains 40 CFU (Colony Forming Units), what does N0 represent?

    <p>The initial number of bacteria in the sample</p> Signup and view all the answers

    Which of the following elements is NOT required as an enzyme cofactor for bacteria?

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

    What type of bacteria is Pseudomonas, a common nosocomial pathogen?

    <p>Obligate Aerobe</p> Signup and view all the answers

    Which of the following is a characteristic of Facultative Anaerobes?

    <p>They can use oxygen, but can also grow in its absence.</p> Signup and view all the answers

    Which trace element is commonly found in tap water and used as an enzyme cofactor?

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

    Which type of bacteria can carry out fermentation regardless of the presence of oxygen?

    <p>Aerotolerant Anaerobes</p> Signup and view all the answers

    Which element is used to form proteins and some vitamins in bacteria?

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

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser