Observing Bacteria Flashcards
What is the primary method for observing bacteria?
Microscopy
True or False: Bacteria can be observed with the naked eye.
False
Fill in the blank: The most common type of microscope used to observe bacteria is the ______ microscope.
light
What is the function of a staining technique in observing bacteria?
To enhance contrast and visibility of bacterial cells.
Name one common stain used for bacterial observation.
Gram stain
What does the Gram stain differentiate between?
Gram-positive and Gram-negative bacteria
Multiple Choice: Which of the following is NOT a type of microscopy used for observing bacteria? A) Electron microscopy B) Fluorescence microscopy C) Infrared microscopy
C) Infrared microscopy
Short Answer: What is the purpose of using a phase-contrast microscope?
To observe live cells without staining.
True or False: Bacteria can be cultured on solid media for observation.
True
What is the role of agar in bacterial culture media?
To provide a solid surface for bacterial growth.
Fill in the blank: Bacteria that require oxygen for growth are called ______ bacteria.
aerobic
What is a colony in the context of bacteria?
A visible mass of bacteria originating from a single cell.
Multiple Choice: Which microscopy technique allows for the visualization of live cells in real time? A) Scanning electron microscopy B) Light microscopy C) Transmission electron microscopy
B) Light microscopy
True or False: All bacteria are harmful to humans.
False
What is the purpose of using a biosafety cabinet when observing pathogenic bacteria?
To protect the user and the environment from exposure.
Short Answer: What is the significance of motility in bacterial observation?
It helps identify bacterial species and their behavior.
Fill in the blank: Bacteria that do not require oxygen are called ______ bacteria.
anaerobic
What is the use of an oil immersion lens in microscopy?
To increase resolution and clarity of the image.
Multiple Choice: Which stain is used to visualize bacterial capsules? A) Gram stain B) Capsule stain C) Acid-fast stain
B) Capsule stain
True or False: Bacteria can be identified by their shape.
True
Short Answer: What are the three basic shapes of bacteria?
Cocci, bacilli, and spirilla.
Fill in the blank: Bacteria that are spherical in shape are called ______.
cocci
What is the purpose of a selective medium in bacterial culture?
To inhibit the growth of certain bacteria while allowing others to grow.
Multiple Choice: Which type of microscopy provides the highest resolution? A) Light microscopy B) Scanning electron microscopy C) Transmission electron microscopy
C) Transmission electron microscopy
True or False: Staining is not necessary for observing bacteria under a microscope.
True
Short Answer: What is the principle behind fluorescence microscopy?
It uses fluorescent dyes to label specific cellular components.
Fill in the blank: The process of spreading a bacterial sample on a slide is called ______.
smearing
What materials are used in the microbiology laboratory exercise?
- Yeast solution
- Euglena prepared slide
- Paramecium prepared slide
- Elodea
- Toothpicks
- Waste beaker of germicide
- Slides
These materials are essential for observing different microorganisms during the lab exercise.
What is the first step in the laboratory procedure?
Prepare a wet mount for cheek, elodea, and yeast cells. Label the slide with organism’s name.
Proper labeling is crucial for identifying the organisms being observed.
How should cheek cells be prepared for examination?
Put a drop of water on a slide, scrape the inside of your cheek with a toothpick, mix the scraping in the drop of water, add a drop of methylene blue, and place a coverslip.
Methylene blue stains the cells, making them more visible under the microscope.
What is the procedure for preparing an Elodea slide?
Use the forceps to remove a young leaf from the tip of the plant, put the leaf in three drops of water on a slide, add a coverslip, and examine with the microscope.
Elodea is a common aquatic plant used in microscopy to observe plant cells.
How should yeast be prepared for microscopic examination?
Put a drop of the yeast solution on a slide, add a drop of methylene blue, and place a coverslip.
Staining helps in visualizing the yeast cells under the microscope.
What are the steps for examining Euglena and Paramecium prepared slides?
Examine with 4X, 10X, and 40X objectives.
Different objectives allow for varying levels of magnification to observe details.
What should not be done with prepared slides after use?
DO NOT DISPOSE PREPARED SLIDES.
This is important for maintaining sample integrity for future observations.
What is the last step in the laboratory procedure?
Clean the objectives with lens paper and lens cleaner.
Cleaning the microscope ensures clear visibility for future users.
