Question 1

Handwashing: 
1. HAIs result from the interaction of three factors. What are these factors?

Accepted Answer

Microorganisms that cause infection  
A susceptible/compromised host  
A means of transmission between the microorganism and host

Question 2

2. Describe how hand washing can reduce HAIs

Accepted Answer

Handwashing removes microorganisms from the hands and breaks the chain of transmission, reducing the spread of HAIs.

Question 3

3. Where do the microbes that cause HAIs come from

Accepted Answer

They can come from the patient, healthcare workers, other people, contaminated equipment, and the healthcare environment.

Question 4

4. Quantify the impact of HAIs.

Accepted Answer

HAIs cause millions of infections and thousands of deaths each year, increasing healthcare costs and hospital stays.

Question 5

5. Describe proper hand washing (who, how, when & where) in the healthcare setting.

Accepted Answer

Healthcare workers should wash their hands before and after patient contact, after touching contaminated materials, and before performing procedures. Wash with soap and water for at least 20 seconds, or use an alcohol-based hand sanitizer when appropriate

Question 6

6. How can hand washing help you and your family stay healthy in everyday life activities?

Accepted Answer

Handwashing removes germs and helps prevent the spread of infections. Wash your hands before eating or preparing food, after using the restroom, after coughing or sneezing, and after touching contaminated surfaces.

Question 7

Waste Disposal in the Microbiology Lab:
1. Why is it important that biohazard waste be disposed of in a biohazard container?

Accepted Answer

To prevent the spread of infectious microorganisms and protect people from exposure.

Question 8

2. Explain why glass should never be placed in the biohazard bag.

Accepted Answer

Glass can puncture the bag and cause cuts or exposure to hazardous materials. It should go in a sharps/broken-glass container.

Question 9

3. Why are finished cultures placed on the clean-up cart and never poured down the sink drain?

Accepted Answer

Cultures may contain living microorganisms that could contaminate the environment or spread infection.

Question 10

4. Why are cultures provided by the lab technician placed on the clean-up cart when finished and not used for the next lab class?

Accepted Answer

They must be properly decontaminated or sterilized before disposal to prevent exposure and contamination.

Question 11

5. Explain why used gloves are disposed of in the biohazard bag.

Accepted Answer

Used gloves may be contaminated with microorganisms, so they must be disposed of as biohazard waste.

Question 12

Contamination:
1. What is a colony and where does it come from?

Accepted Answer

A visible group of microorganisms that grows from one original cell or a small group of cells.

Question 13

2. What is aseptic technique?

Accepted Answer

A: Procedures used to prevent contamination by unwanted microorganisms.

Question 14

3. What is a nosocomial infection?

Accepted Answer

An infection acquired in a healthcare setting, such as a hospital.

Question 15

4. Define HAI.

Accepted Answer

Healthcare-Associated Infection—an infection acquired while receiving healthcare.

Question 16

5. How does aseptic technique relate to the role of health care providers (i.e. nurses and doctors) in the hospital or other health care setting?

Accepted Answer

It helps nurses and doctors prevent the spread of microorganisms and protect patients from infections.

Question 17

ntroduction to Microscopy pre-lab:
1. How many objective lenses does your microscope have and what is their function?

Accepted Answer

Usually 4 objective lenses: 4×, 10×, 40×, and 100×. They magnify the specimen at different levels.

Question 18

2. What is the function of the ocular lenses?

Accepted Answer

They further magnify the image so you can see it through the eyepieces. Usually 10×.

Question 19

3. Define resolving power.

Accepted Answer

The ability of a microscope to distinguish two very close objects as separate.

Question 20

4.  Describe the function of the condenser.

Accepted Answer

t concentrates and focuses light onto the specimen.

Question 21

5.Describe the function of the iris (AKA diaphragm).

Accepted Answer

It controls the amount of light passing through the specimen.

Question 22

6.How do you calculate total magnification?

Accepted Answer

Ocular magnification × Objective magnification = Total magnification.
Example: 10× × 40× = 400×.

Question 23

7. What property of the microscope allows one to observe the fine details of a magnified specimen?

Accepted Answer

Resolving power (resolution).

Question 24

Define: Viewing Live Protozoa 
Nucleus

Accepted Answer

The cell structure that contains genetic material and controls cell activities.

Question 25

Define:
Cytoplasm

Accepted Answer

The jelly-like material inside the cell where many cell activities occur.

Question 26

Define:
Foood vacuole

Accepted Answer

A structure that stores and digests food inside the cell.

Question 27

Define:
Chroloplast

Accepted Answer

A structure containing chlorophyll that allows photosynthesis to occur.

Question 28

Define:
Eye spot

Accepted Answer

A light-sensitive structure that helps an organism detect and capture light.

Question 29

Define:
Flagellum

Accepted Answer

A long, whip-like structure used for movement.

Question 30

Define:
Pseudopodia

Accepted Answer

Temporary extensions of the cell used for movement and capturing food.

Question 31

Define:
Cilia

Accepted Answer

Short, hair-like structures used for movement and moving food.

Question 32

Define:
Feeding grove

Accepted Answer

A specialized groove or opening where food enters the cell.

Question 33

Which structures an be found in Amoeba?

Accepted Answer

Nucleus, cytoplasm, food vacuoles, and pseudopodia.

Question 34

Q: Which structures  can be found in Paramecium?

Accepted Answer

Nucleus, cytoplasm, food vacuoles, cilia, and feeding groove

Question 35

Which structures can be found in Euglena?

Accepted Answer

Nucleus, cytoplasm, chloroplasts, eyespot, and flagellum

Question 36

Which of the following is capable of photosynthesis: Amoeba, Paramecium, or Euglena? Justify your answer.

Accepted Answer

Euglena, because it contains chloroplasts, which allow it to perform photosynthesis.

Question 37

Which one is the smallest?

Accepted Answer

Euglena

Question 38

Which one is the slowest?

Accepted Answer

Amoeba

Question 39

Which one is a phototroph?

Accepted Answer

Euglena

Question 40

Subculturing
Define: sterile

Accepted Answer

Free from all living microorganisms.

Question 41

What is culture media?

Accepted Answer

A nutrient material used to grow microorganisms.

Question 42

Define culture.

Accepted Answer

Microorganisms growing in or on a nutrient medium.

Question 43

Why is agar sometimes added to culture media?

Accepted Answer

make the culture medium solid so microorganisms can grow on its surface.

Question 44

When subculturing, when should the inoculating loop be sterilized and why?

Accepted Answer

Before and after use, to prevent contamination and ensure aseptic technique.

Question 45

What is contamination and list more than one potential source of contamination for your cultures.

Accepted Answer

Contamination is the unwanted introduction of microorganisms. Sources include air, hands, equipment, and improperly sterilized materials.

Question 46

What are each of the following: broth, slant, Petri plate?

Accepted Answer

Broth: Liquid culture medium.  
Slant: Solid agar medium in a tube positioned at an angle.  
Petri plate: Shallow dish containing solid agar medium.

Question 47

Why must broth cultures be handled with extra care?

Accepted Answer

Microorganisms can easily spill or splash, causing contamination.

Question 48

What information should be on your culture labels?

Accepted Answer

Your name/initials, date, and identification of the culture.

Question 49

List two terms used to describe growth in broths and explain what they mean.

Accepted Answer

Turbidity: Cloudiness throughout the broth caused by microbial growth.  
Pellicle: A layer of microbial growth that forms on the surface of the broth.

Question 50

Broth

Accepted Answer

Liquid culture medium.

Question 51

Slant

Accepted Answer

Solid agar medium in a tube positioned at an angle.

Question 52

Petri plate

Accepted Answer

Shallow dish containing solid agar medium.

Question 53

Turbidity

Accepted Answer

Cloudiness throughout the broth caused by microbial growth.

Question 54

Pellicle:

Accepted Answer

A layer of microbial growth that forms on the surface of the broth.

Question 55

Simple Stain:
List at least one basic stain used in the simple stain technique. What color will the cells appear?

Accepted Answer

Methylene blue — cells will appear blue.

Question 56

Why are basic stains attracted to the cell?

Accepted Answer

Basic stains have a" positive charge" and are attracted to the "negative charge" bacterial cell surface.

Question 57

What is a smear?

Accepted Answer

A thin layer of microorganisms spread onto a microscope slide for staining and viewing.

Question 58

List at least three terms used to describe bacterial cell morphology and their meanings.
Answer:

Accepted Answer

Coccus (cocci): Spherical/round cells  
Bacillus (bacilli): Rod-shaped cells  
Spirillum (spirilla): Spiral-shaped cells

Question 59

Coccus (cocci)

Accepted Answer

Spherical/round cells

Question 60

Bacillus (bacilli)

Accepted Answer

Rod-shaped cells

Question 61

Spirillum (spirilla)

Accepted Answer

Spiral-shaped cells

Question 62

Describe the purpose of the simple stain technique.

Accepted Answer

To make bacterial cells easier to see and determine their size, shape, and arrangement under a microscope.

Question 63

Where will you dispose of used slides that did not turn out correctly?

Accepted Answer

Dispose of them in the designated slide disposal/sharps container according to laboratory safety procedures.

Question 64

Disinfection:
Explain the difference between disinfection and sterilization.

Accepted Answer

Disinfection destroys most pathogens on nonliving surfaces. Sterilization destroys all microorganisms, including endospores.

Medical Microbiology

Microbiology Lab Paractical Exam # 1

Question	Answer
Handwashing: 1. HAIs result from the interaction of three factors. What are these factors?	Microorganisms that cause infection A susceptible/compromised host A means of transmission between the microorganism and host
2. Describe how hand washing can reduce HAIs	Handwashing removes microorganisms from the hands and breaks the chain of transmission, reducing the spread of HAIs.
3. Where do the microbes that cause HAIs come from	They can come from the patient, healthcare workers, other people, contaminated equipment, and the healthcare environment.
4. Quantify the impact of HAIs.	HAIs cause millions of infections and thousands of deaths each year, increasing healthcare costs and hospital stays.
5. Describe proper hand washing (who, how, when & where) in the healthcare setting.	Healthcare workers should wash their hands before and after patient contact, after touching contaminated materials, and before performing procedures. Wash with soap and water for at least 20 seconds, or use an alcohol-based hand sanitizer when appropriate
6. How can hand washing help you and your family stay healthy in everyday life activities?	Handwashing removes germs and helps prevent the spread of infections. Wash your hands before eating or preparing food, after using the restroom, after coughing or sneezing, and after touching contaminated surfaces.
Waste Disposal in the Microbiology Lab: 1. Why is it important that biohazard waste be disposed of in a biohazard container?	To prevent the spread of infectious microorganisms and protect people from exposure.
2. Explain why glass should never be placed in the biohazard bag.	Glass can puncture the bag and cause cuts or exposure to hazardous materials. It should go in a sharps/broken-glass container.
3. Why are finished cultures placed on the clean-up cart and never poured down the sink drain?	Cultures may contain living microorganisms that could contaminate the environment or spread infection.
4. Why are cultures provided by the lab technician placed on the clean-up cart when finished and not used for the next lab class?	They must be properly decontaminated or sterilized before disposal to prevent exposure and contamination.
5. Explain why used gloves are disposed of in the biohazard bag.	Used gloves may be contaminated with microorganisms, so they must be disposed of as biohazard waste.
Contamination: 1. What is a colony and where does it come from?	A visible group of microorganisms that grows from one original cell or a small group of cells.
2. What is aseptic technique?	A: Procedures used to prevent contamination by unwanted microorganisms.
3. What is a nosocomial infection?	An infection acquired in a healthcare setting, such as a hospital.
4. Define HAI.	Healthcare-Associated Infection—an infection acquired while receiving healthcare.
5. How does aseptic technique relate to the role of health care providers (i.e. nurses and doctors) in the hospital or other health care setting?	It helps nurses and doctors prevent the spread of microorganisms and protect patients from infections.
ntroduction to Microscopy pre-lab: 1. How many objective lenses does your microscope have and what is their function?	Usually 4 objective lenses: 4×, 10×, 40×, and 100×. They magnify the specimen at different levels.
2. What is the function of the ocular lenses?	They further magnify the image so you can see it through the eyepieces. Usually 10×.
3. Define resolving power.	The ability of a microscope to distinguish two very close objects as separate.
4. Describe the function of the condenser.	t concentrates and focuses light onto the specimen.
5.Describe the function of the iris (AKA diaphragm).	It controls the amount of light passing through the specimen.
6.How do you calculate total magnification?	Ocular magnification × Objective magnification = Total magnification. Example: 10× × 40× = 400×.
7. What property of the microscope allows one to observe the fine details of a magnified specimen?	Resolving power (resolution).
Define: Viewing Live Protozoa Nucleus	The cell structure that contains genetic material and controls cell activities.
Define: Cytoplasm	The jelly-like material inside the cell where many cell activities occur.
Define: Foood vacuole	A structure that stores and digests food inside the cell.
Define: Chroloplast	A structure containing chlorophyll that allows photosynthesis to occur.
Define: Eye spot	A light-sensitive structure that helps an organism detect and capture light.
Define: Flagellum	A long, whip-like structure used for movement.
Define: Pseudopodia	Temporary extensions of the cell used for movement and capturing food.
Define: Cilia	Short, hair-like structures used for movement and moving food.
Define: Feeding grove	A specialized groove or opening where food enters the cell.
Which structures an be found in Amoeba?	Nucleus, cytoplasm, food vacuoles, and pseudopodia.
Q: Which structures can be found in Paramecium?	Nucleus, cytoplasm, food vacuoles, cilia, and feeding groove
Which structures can be found in Euglena?	Nucleus, cytoplasm, chloroplasts, eyespot, and flagellum
Which of the following is capable of photosynthesis: Amoeba, Paramecium, or Euglena? Justify your answer.	Euglena, because it contains chloroplasts, which allow it to perform photosynthesis.
Which one is the smallest?	Euglena
Which one is the slowest?	Amoeba
Which one is a phototroph?	Euglena
Subculturing Define: sterile	Free from all living microorganisms.
What is culture media?	A nutrient material used to grow microorganisms.
Define culture.	Microorganisms growing in or on a nutrient medium.
Why is agar sometimes added to culture media?	make the culture medium solid so microorganisms can grow on its surface.
When subculturing, when should the inoculating loop be sterilized and why?	Before and after use, to prevent contamination and ensure aseptic technique.
What is contamination and list more than one potential source of contamination for your cultures.	Contamination is the unwanted introduction of microorganisms. Sources include air, hands, equipment, and improperly sterilized materials.
What are each of the following: broth, slant, Petri plate?	Broth: Liquid culture medium. Slant: Solid agar medium in a tube positioned at an angle. Petri plate: Shallow dish containing solid agar medium.
Why must broth cultures be handled with extra care?	Microorganisms can easily spill or splash, causing contamination.
What information should be on your culture labels?	Your name/initials, date, and identification of the culture.
List two terms used to describe growth in broths and explain what they mean.	Turbidity: Cloudiness throughout the broth caused by microbial growth. Pellicle: A layer of microbial growth that forms on the surface of the broth.
Broth	Liquid culture medium.
Slant	Solid agar medium in a tube positioned at an angle.
Petri plate	Shallow dish containing solid agar medium.
Turbidity	Cloudiness throughout the broth caused by microbial growth.
Pellicle:	A layer of microbial growth that forms on the surface of the broth.
Simple Stain: List at least one basic stain used in the simple stain technique. What color will the cells appear?	Methylene blue — cells will appear blue.
Why are basic stains attracted to the cell?	Basic stains have a" positive charge" and are attracted to the "negative charge" bacterial cell surface.
What is a smear?	A thin layer of microorganisms spread onto a microscope slide for staining and viewing.
List at least three terms used to describe bacterial cell morphology and their meanings. Answer:	Coccus (cocci): Spherical/round cells Bacillus (bacilli): Rod-shaped cells Spirillum (spirilla): Spiral-shaped cells
Coccus (cocci)	Spherical/round cells
Bacillus (bacilli)	Rod-shaped cells
Spirillum (spirilla)	Spiral-shaped cells
Describe the purpose of the simple stain technique.	To make bacterial cells easier to see and determine their size, shape, and arrangement under a microscope.
Where will you dispose of used slides that did not turn out correctly?	Dispose of them in the designated slide disposal/sharps container according to laboratory safety procedures.
Disinfection: Explain the difference between disinfection and sterilization.	Disinfection destroys most pathogens on nonliving surfaces. Sterilization destroys all microorganisms, including endospores.
Explain the difference between disinfection, antisepsis, and degerming. Answer:	Disinfection: Destroys or reduces pathogens on nonliving surfaces. Antisepsis: Destroys or reduces microbes on living tissue. Degerming: Physically removes microbes from a surface, such as by washing.
Disinfection:	Destroys or reduces pathogens on nonliving surfaces.
Antisepsis:	Destroys or reduces microbes on living tissue.
Degerming:	Physically removes microbes from a surface, such as by washing.
Are either of the microbes used in this experiment endospore formers?	NO.
What is a biofilm and what effect may it have on disinfectant effectiveness?	A biofilm is a community of microbes attached to a surface and surrounded by a protective layer. It can make microbes more resistant to disinfectants.
What effect does organic matter have on the effectiveness of disinfectants?	Organic matter can reduce disinfectant effectiveness by interfering with or inactivating the disinfectant.
What must be considered and how is a disinfectant used correctly?	Consider the type of microbe, surface, disinfectant concentration, contact time, temperature, and organic matter. Use the disinfectant at the correct concentration and for the required contact time.
Streak Plate. Define colony:	A visible group of microorganisms growing from a single cell or group of cells.
Why must the cells be thinned out during the streak plate technique?	To separate individual cells so they can grow into isolated colonies.
What is the importance of the streak plate technique in microbiology?	It is used to isolate and obtain a pure culture of microorganisms.
Why is the inoculating loop sterilized between each streaking section?	To reduce the number of cells and prevent contamination, allowing isolated colonies to form.
Where will you dispose of your group's broth cultures?	In the designated biohazard/disinfectant container according to your lab's disposal procedure.
Micrococcus luteus color	Yellow
Serratia marcescens color	Red/pink
Escherichia coli. color	White
Staphylococcus epidermidis color	White
Micrococcus luteus Description	Yellow, circular, smooth, convex, opaque
Serratia marcescens Description	Red/pink, circular, smooth, convex, opaque
Escherichia coli. Description	White/cream, circular, smooth, convex, opaque
Staphylococcus epidermidis Description	White/cream, circular, smooth, convex, opaque
Gram Stain: List the four reagents used for the Gram stain in the proper order.	1. Crystal violet 2. Iodine 3. Alcohol 4. Safranin
Describe two specific reasons for incorrect Gram stain results.	Over-decolorizing: Gram-positive cells may appear Gram-negative. Under-decolorizing: Gram-negative cells may appear Gram-positive.
Over-decolorizing:	Gram-positive cells may appear Gram-negative.
Under-decolorizing:	Gram-negative cells may appear Gram-positive.
Why is the Gram stain useful in a clinical lab?	It differentiates bacteria as Gram-positive or Gram-negative and helps determine their shape and arrangement.
What bacterial cell structure does the Gram stain tell us about?	The cell wall, especially the peptidoglycan layer.
Describe how Gram-positive and Gram-negative bacterial cell walls differ chemically and structurally.	Gram-positive: Thick peptidoglycan layer; no outer membrane. Gram-negative: Thin peptidoglycan layer; outer membrane containing LPS.
Gram-positive:	Thick peptidoglycan layer; "no outer membrane".
Gram-negative:	Thin peptidoglycan layer; outer membrane containing LPS.
After correctly completing a Gram stain, what color should Gram-negative bacteria be?	Pink/red
Where will you dispose of used slides that did not turn out correctly?	In the designated sharps container, according to lab safety protocol.
What is the expected Gram reaction and morphology for Staphylococcus epidermidis and Escherichia coli?	Staphylococcus epidermidis: Gram-positive cocci, purple, usually in clusters. Escherichia coli: Gram-negative bacilli (rods), pink/red, usually single rods.
Staphylococcus epidermidis: Gram Stain results	Gram-positive cocci, purple, usually in clusters.
Escherichia coli: Gram stain results	Gram-negative bacilli (rods), pink/red, usually single rods.
Oxygen Requirements of Bacteria: Obligate aerobe:	Requires oxygen (O₂) to grow.
Facultative anaerobe:	Can grow with or without oxygen, but grows better with oxygen.
Obligate anaerobe:	Cannot tolerate oxygen; oxygen is harmful or deadly.
Aerotolerant:	Does not use oxygen but can tolerate its presence.
Microaerophile:	Requires oxygen, but only at low concentrations.
Antimicrobial Testing : 1. What is meant by Minimal Inhibitory Concentration (MIC)?	The lowest concentration of an antibiotic that prevents visible growth of a microorganism.
Compare and contrast the E-test and Kirby-Bauer test.	Both test antibiotic susceptibility. The E-test uses an antibiotic gradient strip and determines the MIC. The Kirby-Bauer test uses antibiotic disks and measures the zone of inhibition to classify bacteria as susceptible, intermediate, or resistant.
How do you properly apply the E-test strip to the inoculated plate?	Place the E-test strip directly onto the surface of the inoculated agar, with the antibiotic concentration scale facing upward. Press it gently so the entire strip contacts the agar.
What is the mode of action for each antibiotic?	Penicillin: Inhibits bacterial cell-wall synthesis. Ampicillin: Inhibits bacterial cell-wall synthesis. Tetracycline: Inhibits protein synthesis by binding the 30S ribosomal subunit. Trimethoprim/sulfa: Blocks folic acid synthesis, inhibiting bacterial
Penicillin:	Inhibits bacterial cell-wall synthesis.
Ampicillin:	Inhibits bacterial cell-wall synthesis.
Tetracycline:	Inhibits protein synthesis by binding the 30S ribosomal subunit.
Trimethoprim/sulfa:	Blocks folic acid synthesis, inhibiting bacterial growth.
Why won't these antibiotics help viral infections such as colds, COVID-19, and influenza?	Antibiotics target bacterial structures or processes. Viruses do not have these bacterial targets, so antibiotics do not kill or stop viruses.
What is antibiotic resistance and how can you help reduce this problem?	Antibiotic resistance occurs when bacteria become able to survive antibiotics. Help reduce it by using antibiotics only when prescribed, taking them exactly as directed, and never sharing or unnecessarily using antibiotics.
"Staphyl" meaning:	bunch of grapes
"Streto" meaning:	twisted
"Pro " meaning:	before
"Karyote" meaning:	nut" , "kernel", "core", or "nuclues"
"Eu" meaning:	"true"
" Epi" meaning:	"over, upon, outer"
"derm" meaning:	"skin"
"ose" meaning:	"sugar"
"ase" meaning:	"enzymes"
"saccharide" meaning:	"sugar"

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