Observing Bacteria

Question 1

What is the primary method for observing bacteria?

Answer 1

Microscopy

Question 2

True or False: Bacteria can be observed with the naked eye.

Answer 2

False

Question 3

Fill in the blank: The most common type of microscope used to observe bacteria is the ______ microscope.

Answer 3

light

Question 4

What is the function of a staining technique in observing bacteria?

Answer 4

To enhance contrast and visibility of bacterial cells.

Question 5

Name one common stain used for bacterial observation.

Answer 5

Gram stain

Question 6

What does the Gram stain differentiate between?

Answer 6

Gram-positive and Gram-negative bacteria

Question 7

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

Answer 7

C) Infrared microscopy

Question 8

Short Answer: What is the purpose of using a phase-contrast microscope?

Answer 8

To observe live cells without staining.

Question 9

True or False: Bacteria can be cultured on solid media for observation.

Answer 9

True

Question 10

What is the role of agar in bacterial culture media?

Answer 10

To provide a solid surface for bacterial growth.

Question 11

Fill in the blank: Bacteria that require oxygen for growth are called ______ bacteria.

Answer 11

aerobic

Question 12

What is a colony in the context of bacteria?

Answer 12

A visible mass of bacteria originating from a single cell.

Question 13

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

Answer 13

B) Light microscopy

Question 14

True or False: All bacteria are harmful to humans.

Answer 14

False

Question 15

What is the purpose of using a biosafety cabinet when observing pathogenic bacteria?

Answer 15

To protect the user and the environment from exposure.

Question 16

Short Answer: What is the significance of motility in bacterial observation?

Answer 16

It helps identify bacterial species and their behavior.

Question 17

Fill in the blank: Bacteria that do not require oxygen are called ______ bacteria.

Answer 17

anaerobic

Question 18

What is the use of an oil immersion lens in microscopy?

Answer 18

To increase resolution and clarity of the image.

Question 19

Multiple Choice: Which stain is used to visualize bacterial capsules? A) Gram stain B) Capsule stain C) Acid-fast stain

Answer 19

B) Capsule stain

Question 20

True or False: Bacteria can be identified by their shape.

Answer 20

True

Question 21

Short Answer: What are the three basic shapes of bacteria?

Answer 21

Cocci, bacilli, and spirilla.

Question 22

Fill in the blank: Bacteria that are spherical in shape are called ______.

Answer 22

cocci

Question 23

What is the purpose of a selective medium in bacterial culture?

Answer 23

To inhibit the growth of certain bacteria while allowing others to grow.

Question 24

Multiple Choice: Which type of microscopy provides the highest resolution? A) Light microscopy B) Scanning electron microscopy C) Transmission electron microscopy

Answer 24

C) Transmission electron microscopy

Question 25

True or False: Staining is not necessary for observing bacteria under a microscope.

Answer 25

True

Question 26

Short Answer: What is the principle behind fluorescence microscopy?

Answer 26

It uses fluorescent dyes to label specific cellular components.

Question 27

Fill in the blank: The process of spreading a bacterial sample on a slide is called ______.

Answer 27

smearing

Question 28

What materials are used in the microbiology laboratory exercise?

Answer 28

* Yeast solution * Euglena prepared slide * Paramecium prepared slide * Elodea * Toothpicks * Waste beaker of germicide * Slides ## Footnote These materials are essential for observing different microorganisms during the lab exercise.

Question 29

What is the first step in the laboratory procedure?

Answer 29

Prepare a wet mount for cheek, elodea, and yeast cells. Label the slide with organism's name. ## Footnote Proper labeling is crucial for identifying the organisms being observed.

Question 30

How should cheek cells be prepared for examination?

Answer 30

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. ## Footnote Methylene blue stains the cells, making them more visible under the microscope.

Question 31

What is the procedure for preparing an Elodea slide?

Answer 31

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. ## Footnote Elodea is a common aquatic plant used in microscopy to observe plant cells.

Question 32

How should yeast be prepared for microscopic examination?

Answer 32

Put a drop of the yeast solution on a slide, add a drop of methylene blue, and place a coverslip. ## Footnote Staining helps in visualizing the yeast cells under the microscope.

Question 33

What are the steps for examining Euglena and Paramecium prepared slides?

Answer 33

Examine with 4X, 10X, and 40X objectives. ## Footnote Different objectives allow for varying levels of magnification to observe details.

Question 34

What should not be done with prepared slides after use?

Answer 34

DO NOT DISPOSE PREPARED SLIDES. ## Footnote This is important for maintaining sample integrity for future observations.

Question 35

What is the last step in the laboratory procedure?

Answer 35

Clean the objectives with lens paper and lens cleaner. ## Footnote Cleaning the microscope ensures clear visibility for future users.