Study Guide for Brock Biology of
Microorganisms, 15th Edition (Madigan
et al., ISBN: 9781292235103) aligned
with a 2026/2027 syllabus
Unit 1: Principles of Microbiology
1. What are the three domains of life according to Carl Woese?
ANSWER ✓ Bacteria, Archaea, Eukarya.
2. Which type of microscopy would you use to observe living, unstained bacterial cells?
ANSWER ✓ Phase-contrast microscopy.
3. Name the two major types of bacterial cell wall structures and their Gram stain
reaction.
ANSWER ✓ Gram-positive (thick peptidoglycan, stains purple) and Gram-negative (thin
peptidoglycan + outer membrane, stains pink/red).
4. What is the function of lipopolysaccharide (LPS) in Gram-negative bacteria?
ANSWER ✓ LPS is an endotoxin that contributes to structural integrity and protects
against host immune defenses.
5. Which structure mediates bacterial attachment to surfaces and is made of protein
subunits?
ANSWER ✓ Fimbriae (or pili).
6. What is the difference between a capsule and a slime layer?
ANSWER ✓ Capsule is tightly bound and organized; slime layer is loosely attached and
diffuse.
7. Which domain has ether-linked isoprenoid chains in its membrane lipids?
ANSWER ✓ Archaea.
, 8. What is the key structural component of peptidoglycan that is attacked by lysozyme?
ANSWER ✓ Beta-1,4 glycosidic bonds between N-acetylglucosamine (NAG) and N-
acetylmuramic acid (NAM).
9. How does a bacterial endospore differ from a vegetative cell?
ANSWER ✓ Endospore is metabolically inactive, heat-resistant, and contains calcium
dipicolinate.
10. Name two medically important endospore-forming genera.
ANSWER ✓ Bacillus and Clostridium.
11. What is the resolution limit of a light microscope?
ANSWER ✓ Approximately 0.2 micrometers (200 nm).
12. Which stain differentiates bacteria based on mycolic acid in their cell wall?
ANSWER ✓ Acid-fast stain (e.g., for Mycobacterium).
Unit 2: Microbial Growth, Nutrition, and Metabolism
13. What are the four cardinal temperatures for a microorganism?
ANSWER ✓ Minimum, optimum, maximum, and (in some definitions) maximum for
growth.
14. Name the five classes of microorganisms based on optimal growth temperature.
ANSWER ✓ Psychrophile, psychrotroph, mesophile, thermophile, hyperthermophile.
15. What is the difference between an obligate aerobe and a facultative anaerobe?
ANSWER ✓ Obligate aerobe requires O2; facultative anaerobe can grow with or
without O2 but better with.
16. Which enzyme detoxifies hydrogen peroxide?
ANSWER ✓ Catalase (breaks H2O2 into H2O and O2).
17. What is the function of the electron transport chain in aerobic respiration?
ANSWER ✓ Generates proton motive force for ATP synthesis via oxidative
phosphorylation.
18. In glycolysis, how many net ATP are produced per glucose?
ANSWER ✓ 2 ATP (net).
Microorganisms, 15th Edition (Madigan
et al., ISBN: 9781292235103) aligned
with a 2026/2027 syllabus
Unit 1: Principles of Microbiology
1. What are the three domains of life according to Carl Woese?
ANSWER ✓ Bacteria, Archaea, Eukarya.
2. Which type of microscopy would you use to observe living, unstained bacterial cells?
ANSWER ✓ Phase-contrast microscopy.
3. Name the two major types of bacterial cell wall structures and their Gram stain
reaction.
ANSWER ✓ Gram-positive (thick peptidoglycan, stains purple) and Gram-negative (thin
peptidoglycan + outer membrane, stains pink/red).
4. What is the function of lipopolysaccharide (LPS) in Gram-negative bacteria?
ANSWER ✓ LPS is an endotoxin that contributes to structural integrity and protects
against host immune defenses.
5. Which structure mediates bacterial attachment to surfaces and is made of protein
subunits?
ANSWER ✓ Fimbriae (or pili).
6. What is the difference between a capsule and a slime layer?
ANSWER ✓ Capsule is tightly bound and organized; slime layer is loosely attached and
diffuse.
7. Which domain has ether-linked isoprenoid chains in its membrane lipids?
ANSWER ✓ Archaea.
, 8. What is the key structural component of peptidoglycan that is attacked by lysozyme?
ANSWER ✓ Beta-1,4 glycosidic bonds between N-acetylglucosamine (NAG) and N-
acetylmuramic acid (NAM).
9. How does a bacterial endospore differ from a vegetative cell?
ANSWER ✓ Endospore is metabolically inactive, heat-resistant, and contains calcium
dipicolinate.
10. Name two medically important endospore-forming genera.
ANSWER ✓ Bacillus and Clostridium.
11. What is the resolution limit of a light microscope?
ANSWER ✓ Approximately 0.2 micrometers (200 nm).
12. Which stain differentiates bacteria based on mycolic acid in their cell wall?
ANSWER ✓ Acid-fast stain (e.g., for Mycobacterium).
Unit 2: Microbial Growth, Nutrition, and Metabolism
13. What are the four cardinal temperatures for a microorganism?
ANSWER ✓ Minimum, optimum, maximum, and (in some definitions) maximum for
growth.
14. Name the five classes of microorganisms based on optimal growth temperature.
ANSWER ✓ Psychrophile, psychrotroph, mesophile, thermophile, hyperthermophile.
15. What is the difference between an obligate aerobe and a facultative anaerobe?
ANSWER ✓ Obligate aerobe requires O2; facultative anaerobe can grow with or
without O2 but better with.
16. Which enzyme detoxifies hydrogen peroxide?
ANSWER ✓ Catalase (breaks H2O2 into H2O and O2).
17. What is the function of the electron transport chain in aerobic respiration?
ANSWER ✓ Generates proton motive force for ATP synthesis via oxidative
phosphorylation.
18. In glycolysis, how many net ATP are produced per glucose?
ANSWER ✓ 2 ATP (net).
