chapter 6

Question 1

Growth Requirements

Answer 1

Nutrients & Chemical Requirements
Oxygen Requirements:
Nitrogen Requirements:
Physical Requirements:
pH Requirements:
Water Requirements:
Associations & Biofilms:

Question 2

Microbial growth refers to

Answer 2

an increase in population size rather than individual cell size.

Question 3

Microbes require

Answer 3

carbon, oxygen, nitrogen, and hydrogen to build cellular structures.

Question 4

Carbon sources:

Answer 4

autotrophs and heterotrophs

Question 5

Autotrophs

Answer 5

Use inorganic carbon (CO₂).

Question 6

Heterotrophs

Answer 6

Obtain carbon from organic compounds.

Question 7

Energy sources:

Answer 7

Phototrophs: Use light energy.

Chemotrophs: Obtain energy from chemical reactions.

Question 8

Electron sources:

Answer 8

Organotrophs and Lithotrophs

Question 9

Organotrophs

Answer 9

Get electrons from organic molecules.

Question 10

Lithotrophs

Answer 10

Get electrons from inorganic sources.

Question 11

Oxygen Requirements:

Answer 11

Obligate aerobes:
Obligate anaerobes:
Facultative anaerobes: .
Aerotolerant anaerobes:
Microaerophiles:

Question 12

Obligate aerobes:

Answer 12

Require oxygen.

Question 13

Obligate anaerobes:

Answer 13

Oxygen is toxic to them.

Question 14

Facultative anaerobes

Answer 14

Prefer oxygen but can grow without it.

Question 15

Aerotolerant anaerobes:

Answer 15

Can survive in oxygen but don’t use it.

Question 16

Microaerophiles

Answer 16

Require low levels of oxygen.

Question 17

Nitrogen Requirements:

Answer 17

Essential for nucleotides and proteins.
Nitrogen fixation by certain bacteria is crucial for life on Earth.

Question 18

Physical Requirements:

Answer 18

temp ph and water

Question 19

how does temp play a role

Answer 19

Affects enzymes and membranes.

Question 20

Psychrophiles

Answer 20

Cold-loving.

Question 21

Mesophiles

Answer 21

Moderate temperatures (most human pathogens).

Question 22

Thermophiles

Answer 22

Heat-loving.

Question 23

Hyperthermophiles

Answer 23

Extreme heat.

Question 24

Neutrophiles

Answer 24

Prefer neutral pH.

Question 25

Acidophiles

Answer 25

Thrive in acidic environments.

Question 26

Alkalinophiles

Answer 26

Live in alkaline environments.

Question 27

Water Requirements:

Answer 27

Osmotic pressure: Affects water movement. Hydrostatic pressure: Barophiles thrive under extreme pressure.

Question 28

Antagonistic relationships:

Answer 28

One organism harms another.

Question 29

Synergistic relationships:

Answer 29

Organisms benefit from living together.

Question 30

Symbiotic relationships

Answer 30

Interdependent organisms.

Question 31

Biofilms

Answer 31

Microbial communities that enhance survival.

Question 32

Defined Media:

Answer 32

Exact chemical composition is known.

Question 33

Complex Media:

Answer 33

Contains unknown compositions (e.g., yeast extract).

Question 34

Selective Media:

Answer 34

Encourages growth of certain microbes while inhibiting others.

Question 35

Differential Media

Answer 35

Helps distinguish between different microbes based on visible changes.

Question 36

Anaerobic Media:

Answer 36

Supports the growth of anaerobes.

Question 37

Transport Media:

Answer 37

Used to preserve specimens during transport.

Question 38

Log Phase:

Answer 38

Rapid cell division and exponential growth.

Question 39

Lag Phase

Answer 39

Microbes adjust to new conditions; no significant growth.

Question 40

Stationary Phase:

Answer 40

Nutrient depletion slows growth; cell death equals cell division.