3.2.5 Microbiology

• What is the study of microscopic organisms called?

  Microbiology
• What are the three main types of microorganisms?

  Bacteria, fungi, viruses
• What type of organisms are fungi?

  Eukaryotic, multicellular
• Match the microorganism with its key feature:

  Bacteria ↔️ Lack a true nucleus

  Fungi ↔️ Have membrane-bound organelles

  Viruses ↔️ Require a host cell
• Sterilization involves the complete elimination of all microorganisms, including spores.


  True
• Incubation involves placing the inoculated medium in an incubator at a controlled temperature and humidity.

  True
• During observation, cultures are examined for colonies and growth characteristics
• Match the step in culturing microorganisms with its purpose:

  Inoculation ↔️ Start microbial growth

  Incubation ↔️ Facilitate optimal growth

  Observation ↔️ Identify and analyze microorganisms
• What are the four main types of microorganisms studied in microbiology?

  Bacteria, viruses, fungi, protozoa
• Fungi are eukaryotic, multicellular organisms that include yeasts, molds, and mushrooms
• Aseptic techniques are used to prevent contamination by pathogenic microorganisms.


  True
• Sterilization involves the complete elimination of all microorganisms, including spores
• What is a growth medium used in microbiology?

  Nutrient broth or agar plate
• Match the type of microscopy with its description:

  Light microscopy ↔️ Uses visible light and lenses

  Electron microscopy ↔️ Uses beams of electrons
• What type of staining technique differentiates bacteria based on their cell wall composition?

  Gram staining
• Serial dilution and plate counting only count viable cells.


  True
• Match the microbial counting method with its characteristic:

  Direct count ↔️ Counts live and dead cells

  Serial dilution and plate counting ↔️ Estimates viable cells only
• Factors affecting microbial growth include temperature, pH, oxygen availability, and nutrients
• High temperatures denature enzymes, while low temperatures slow metabolism
• Match the oxygen requirement with the type of organism:

  Aerobes ↔️ Require oxygen

  Anaerobes ↔️ Grow without oxygen
• What are the key fields where microbiology plays a significant role?

  Health, disease, industries
• What are the three main types of microorganisms?

  Bacteria, fungi, viruses
• Fungi are eukaryotic and include yeasts, molds, and mushrooms
• Arrange the following aseptic techniques in order from most to least rigorous:

  1️⃣ Sterilization

  2️⃣ Disinfection

  3️⃣ Antisepsis

  4️⃣ Sanitation
• Disinfection reduces the number of microorganisms to a safe level.


  True
• Arrange the steps involved in inoculation and culturing of microorganisms in the correct order:

  1️⃣ Inoculation

  2️⃣ Incubation

  3️⃣ Observation
• What are common techniques used for inoculation?

  Streaking or spreading
• During observation, growth characteristics are recorded to identify microorganisms
• What are two key techniques used in inoculation?

  Streaking and spreading
• The purpose of incubation is to facilitate optimal microbial growth
• What type of microscopy uses visible light and lenses?

  Light microscopy
• Selective media promotes growth of certain microbes while inhibiting others
• Light microscopy provides higher resolution than electron microscopy.

  False
• What is used to count cells directly in a direct count method?

  Hemocytometer
• In serial dilution and plate counting, the original population is estimated as colony forming units
• Serial dilution and plate counting only counts viable cells.

  True
• What is the formula for calculating original CFU/mL in serial dilution and plate counting?

  $(Number of colonies / Volume plated) \times Dilution factor$
• The original CFU/mL is calculated by multiplying the number of colonies by the dilution factor
• The direct count method uses a hemocytometer or counting chamber.


  True
• What does CFU stand for in microbiology?

  Colony Forming Units