Microbiology Lab Practical 1 Study
Guide with Complete Solutions
Why is it important to flame sterilize an inoculating loop before and after use?
✔✔To prevent cross-contamination between samples.
What is the main role of the primary antibody in an ELISA test?
✔✔To bind specifically to the target antigen.
What does a positive catalase test produce?
✔✔Bubbles of oxygen when hydrogen peroxide is applied.
What type of bacteria are capable of forming biofilms?
✔✔Bacteria that adhere to surfaces and produce extracellular polymeric substances.
Why is refrigeration used to store bacterial cultures?
✔✔To slow down bacterial growth and preserve the cultures.
1
,What is the function of bacterial flagella?
✔✔To enable motility in liquid environments.
What does a pink colony on MacConkey agar indicate?
✔✔The organism ferments lactose.
What type of organisms require oxygen for growth but at lower concentrations than atmospheric
levels?
✔✔Microaerophiles.
What does the term “asepsis” refer to in microbiology?
✔✔The absence of pathogenic microorganisms.
What is the purpose of a zone of inhibition in antibiotic testing?
✔✔To measure bacterial susceptibility to an antibiotic.
What kind of microorganisms are detected using Sabouraud dextrose agar?
✔✔Fungi, including yeasts and molds.
2
, What is the main characteristic of acid-fast bacteria?
✔✔They have waxy, lipid-rich cell walls.
Why are serial dilutions used in microbiology?
✔✔To estimate the number of bacteria in a sample by reducing concentration.
What is the term for bacteria that grow best at very cold temperatures?
✔✔Psychrophiles.
What is the role of a bacterial capsule in disease?
✔✔To protect bacteria from the host immune system.
What is the function of endospores in bacteria?
✔✔To survive extreme environmental conditions like heat or desiccation.
What does a clear zone around colonies on blood agar indicate?
✔✔Beta hemolysis, or complete lysis of red blood cells.
3
Guide with Complete Solutions
Why is it important to flame sterilize an inoculating loop before and after use?
✔✔To prevent cross-contamination between samples.
What is the main role of the primary antibody in an ELISA test?
✔✔To bind specifically to the target antigen.
What does a positive catalase test produce?
✔✔Bubbles of oxygen when hydrogen peroxide is applied.
What type of bacteria are capable of forming biofilms?
✔✔Bacteria that adhere to surfaces and produce extracellular polymeric substances.
Why is refrigeration used to store bacterial cultures?
✔✔To slow down bacterial growth and preserve the cultures.
1
,What is the function of bacterial flagella?
✔✔To enable motility in liquid environments.
What does a pink colony on MacConkey agar indicate?
✔✔The organism ferments lactose.
What type of organisms require oxygen for growth but at lower concentrations than atmospheric
levels?
✔✔Microaerophiles.
What does the term “asepsis” refer to in microbiology?
✔✔The absence of pathogenic microorganisms.
What is the purpose of a zone of inhibition in antibiotic testing?
✔✔To measure bacterial susceptibility to an antibiotic.
What kind of microorganisms are detected using Sabouraud dextrose agar?
✔✔Fungi, including yeasts and molds.
2
, What is the main characteristic of acid-fast bacteria?
✔✔They have waxy, lipid-rich cell walls.
Why are serial dilutions used in microbiology?
✔✔To estimate the number of bacteria in a sample by reducing concentration.
What is the term for bacteria that grow best at very cold temperatures?
✔✔Psychrophiles.
What is the role of a bacterial capsule in disease?
✔✔To protect bacteria from the host immune system.
What is the function of endospores in bacteria?
✔✔To survive extreme environmental conditions like heat or desiccation.
What does a clear zone around colonies on blood agar indicate?
✔✔Beta hemolysis, or complete lysis of red blood cells.
3
