GTC BIO 2117 VERIFIED EXAM SOLUTIONS - COMPREHENSIVE
QUESTIONS AND ANSWERS - CURRENT VERSION
1. Q: Who is considered the "Father of Microbiology" for first observing
bacteria?
ANSWER Antonie van Leeuwenhoek.
2. Q: What did Louis Pasteur disprove with his swan-neck flask
experiments?
ANSWER Spontaneous generation (abiogenesis).
3. Q: What is the germ theory of disease?
ANSWER The theory that microorganisms are the cause of many
diseases.
4. Q: Who developed the first vaccine (for smallpox)?
ANSWER Edward Jenner.
5. Q: What contribution did Robert Koch make to microbiology?
ANSWER He developed Koch's postulates to prove the causative agent of
disease and isolated Mycobacterium tuberculosis.
6. Q: What are Koch's postulates?
ANSWER (1) The microbe must be present in every case of the disease.
(2) It must be isolated and grown in pure culture. (3) It must cause the
disease when inoculated into a healthy host. (4) It must be re-isolated
from the infected host.
7. Q: What is bioremediation?
ANSWER The use of microorganisms to remove or neutralize pollutants
from the environment.
8. Q: What is a pathogen?
ANSWER A disease-causing microorganism.
9. Q: What is normal microbiota (flora)?
ANSWER Microorganisms that colonize the body without normally
causing disease.
,10. Q: What is aseptic technique?
ANSWER Practices used to prevent contamination by unwanted
microorganisms.
11. Q: What did Joseph Lister pioneer?
ANSWER Antiseptic surgery using carbolic acid (phenol).
12. Q: What is biotechnology?
ANSWER The use of microorganisms or their components to make useful
products.
13. Q: What is recombinant DNA technology?
ANSWER Inserting genes from one organism into another to produce
desired proteins.
14. Q: What is a colony in microbiology?
ANSWER A visible mass of microorganisms growing on a solid medium,
arising from a single cell or group of cells.
15. Q: What is a pure culture?
ANSWER A population of cells arising from a single cell, with no other
species present.
16. Q: What is the difference between a prokaryote and a eukaryote?
ANSWER Prokaryotes lack a membrane-bound nucleus and organelles;
eukaryotes have both.
17. Q: What are the two major groups of prokaryotes?
ANSWER Bacteria and Archaea.
18. Q: What is a microbe?
ANSWER A living organism too small to be seen with the naked eye.
19. Q: What is pasteurization?
ANSWER Heating a liquid to a temperature that kills harmful microbes
without altering flavor.
20. Q: What is the importance of Penicillium in microbiology history?
ANSWER Alexander Fleming discovered it produced penicillin, the first
antibiotic.
Chapter 2: Microscopy and Staining (Questions 21–40)
, 21. Q: What is the resolving power of a microscope?
ANSWER The ability to distinguish two adjacent objects as separate.
22. Q: What is the maximum magnification of a light microscope?
ANSWER About 1000–2000x.
23. Q: What is the purpose of a simple stain?
ANSWER To increase contrast and visualize cell shape and arrangement.
24. Q: What is the Gram stain?
ANSWER A differential stain that divides bacteria into Gram-positive
(purple) and Gram-negative (pink).
25. Q: Why do Gram-positive bacteria retain the crystal violet dye?
ANSWER They have a thick peptidoglycan layer that traps the dye-iodine
complex.
26. Q: What color do Gram-negative bacteria appear after Gram staining?
ANSWER Pink or red (from the safranin counterstain).
27. Q: What is the acid-fast stain used for?
ANSWER To identify mycobacteria like Mycobacterium tuberculosis.
28. Q: What is the primary dye in the acid-fast stain?
ANSWER Carbolfuchsin.
29. Q: What is a capsule stain?
ANSWER A negative staining technique used to visualize the gelatinous
capsule around some bacteria.
30. Q: What is the endospore stain used for?
ANSWER To detect endospores, which are resistant to normal staining.
31. Q: What color do endospores appear in a properly performed
endospore stain?
ANSWER Green (with malachite green), while vegetative cells are
pink/red.
32. Q: What is a flagella stain?
ANSWER A stain that increases the diameter of flagella so they can be
seen under a light microscope.
33. Q: What is bright-field microscopy?
ANSWER The most common type of light microscopy where specimens
appear dark against a bright background.
QUESTIONS AND ANSWERS - CURRENT VERSION
1. Q: Who is considered the "Father of Microbiology" for first observing
bacteria?
ANSWER Antonie van Leeuwenhoek.
2. Q: What did Louis Pasteur disprove with his swan-neck flask
experiments?
ANSWER Spontaneous generation (abiogenesis).
3. Q: What is the germ theory of disease?
ANSWER The theory that microorganisms are the cause of many
diseases.
4. Q: Who developed the first vaccine (for smallpox)?
ANSWER Edward Jenner.
5. Q: What contribution did Robert Koch make to microbiology?
ANSWER He developed Koch's postulates to prove the causative agent of
disease and isolated Mycobacterium tuberculosis.
6. Q: What are Koch's postulates?
ANSWER (1) The microbe must be present in every case of the disease.
(2) It must be isolated and grown in pure culture. (3) It must cause the
disease when inoculated into a healthy host. (4) It must be re-isolated
from the infected host.
7. Q: What is bioremediation?
ANSWER The use of microorganisms to remove or neutralize pollutants
from the environment.
8. Q: What is a pathogen?
ANSWER A disease-causing microorganism.
9. Q: What is normal microbiota (flora)?
ANSWER Microorganisms that colonize the body without normally
causing disease.
,10. Q: What is aseptic technique?
ANSWER Practices used to prevent contamination by unwanted
microorganisms.
11. Q: What did Joseph Lister pioneer?
ANSWER Antiseptic surgery using carbolic acid (phenol).
12. Q: What is biotechnology?
ANSWER The use of microorganisms or their components to make useful
products.
13. Q: What is recombinant DNA technology?
ANSWER Inserting genes from one organism into another to produce
desired proteins.
14. Q: What is a colony in microbiology?
ANSWER A visible mass of microorganisms growing on a solid medium,
arising from a single cell or group of cells.
15. Q: What is a pure culture?
ANSWER A population of cells arising from a single cell, with no other
species present.
16. Q: What is the difference between a prokaryote and a eukaryote?
ANSWER Prokaryotes lack a membrane-bound nucleus and organelles;
eukaryotes have both.
17. Q: What are the two major groups of prokaryotes?
ANSWER Bacteria and Archaea.
18. Q: What is a microbe?
ANSWER A living organism too small to be seen with the naked eye.
19. Q: What is pasteurization?
ANSWER Heating a liquid to a temperature that kills harmful microbes
without altering flavor.
20. Q: What is the importance of Penicillium in microbiology history?
ANSWER Alexander Fleming discovered it produced penicillin, the first
antibiotic.
Chapter 2: Microscopy and Staining (Questions 21–40)
, 21. Q: What is the resolving power of a microscope?
ANSWER The ability to distinguish two adjacent objects as separate.
22. Q: What is the maximum magnification of a light microscope?
ANSWER About 1000–2000x.
23. Q: What is the purpose of a simple stain?
ANSWER To increase contrast and visualize cell shape and arrangement.
24. Q: What is the Gram stain?
ANSWER A differential stain that divides bacteria into Gram-positive
(purple) and Gram-negative (pink).
25. Q: Why do Gram-positive bacteria retain the crystal violet dye?
ANSWER They have a thick peptidoglycan layer that traps the dye-iodine
complex.
26. Q: What color do Gram-negative bacteria appear after Gram staining?
ANSWER Pink or red (from the safranin counterstain).
27. Q: What is the acid-fast stain used for?
ANSWER To identify mycobacteria like Mycobacterium tuberculosis.
28. Q: What is the primary dye in the acid-fast stain?
ANSWER Carbolfuchsin.
29. Q: What is a capsule stain?
ANSWER A negative staining technique used to visualize the gelatinous
capsule around some bacteria.
30. Q: What is the endospore stain used for?
ANSWER To detect endospores, which are resistant to normal staining.
31. Q: What color do endospores appear in a properly performed
endospore stain?
ANSWER Green (with malachite green), while vegetative cells are
pink/red.
32. Q: What is a flagella stain?
ANSWER A stain that increases the diameter of flagella so they can be
seen under a light microscope.
33. Q: What is bright-field microscopy?
ANSWER The most common type of light microscopy where specimens
appear dark against a bright background.
