CHAP 8

Question 1

TRUE/FALSE

All living organisms require nutrients to sustain life.

Answer 1

TRUE

Question 2

What is needed to carry our normal metabolic processes?

Answer 2

Water

Question 3

What are microorganisms that grow best at high temperatures?

Answer 3

Thermophiles

Question 4

What are microbes that grow best at moderate temperatures?

Answer 4

Mesophiles

Question 5

What prefers cold temperatures like deep ocean water?

Answer 5

Psychrophiles

Question 6

What do you call a particular group of psychrophiles, that prefer refrigerator temperature like 4 degrees celsius?

Answer 6

Psychotrophs

Question 7

What prefer warm temperatures but can endure very cold or even freezing temperatures?

Answer 7

Psychroduric organisms

Question 8

What refers to the acidity or alkalinity of a solution?

Answer 8

pH

Question 9

TRUE/FALSE
Some microorganisms prefer a neutral or slightly alkaline growth medium.

Answer 9

FALSE (Most)

Question 10

What prefers a pH of 2 to 5?

Answer 10

Acidophiles

Question 11

What prefer a pH of >8.5?

Answer 11

Alkaliphiles

Question 12

What is the pressure that is exerted on a cell membrane by solutions both inside and outside the cell?

Answer 12

Osmotic pressure

Question 13

What is the movement of a solvent, through permeable membrane, from a lower concentration of solutes to a higher concentration of solutes?

Answer 13

Osmosis

Question 14

What is a condition in which the cell membrane and cytoplasm of a cell shrink away from the cell wall?

Answer 14

Plasmolysis

Question 15

What occurs when bacteria with rigid cell walls are placed in a hypertonic solution?

Answer 15

Plasmolysis

Question 16

When the concentration of solutes outside a cell is less than that of solutes inside a cell, the solution in which the cell is suspended is called?

Answer 16

hypotonic

Question 17

If a bacterial cell is placed into a hypotonic solution and bursts, the cytoplasm escapes and this process is called?

Answer 17

plasmoptysis

Question 18

A solution is said to be ________ when the concentration of solutes outside a cell equals the concentration of solutes inside the cell.

Answer 18

isotonic

Question 19

Organisms that prefer to live in salty environments are called?

Answer 19

halophilic organisms

Question 20

Organisms that do not prefer to live in salty environments but are capable of surviving in salty environments are called?

Answer 20

haloduric organisms

Question 21

What prefer the same atmosphere that humans do?

Answer 21

Obligate aerobes

Question 22

What require reduced concentrations of oxygen?

Answer 22

Microaerophiles

Question 23

What are killed by the presence of oxygen?

Answer 23

Obligate anaerobes

Question 24

What require increased concentrations of CO2?

Answer 24

Capnophiles

Question 25

Bacteria divide by _____________ (one cell divides to become two cells) when they reach their optimum size.

Answer 25

Binary Fission

Question 26

The time it takes for one cell to become two cells is called the?

Answer 26

generation time

Question 27

What are used in microbiology laboratories to culture bacteria?

Answer 27

Media

Question 28

If media is prepared in the laboratories, they are referred to as?

Answer 28

Artificial media or synthetic media

Question 29

TRUE/FALSE A chemically defined medium is one in which all ingredients are known.

Answer 29

TRUE

Question 30

What is a broth or solid containing a rich supply of special nutrients that promote the growth of fastidious organisms, for example, chocolate agar?

Answer 30

Enriched medium

Question 31

What has added inhibitors that discourage growth of certain organisms while allowing the growth of a desired organism, for example, PEA agar?

Answer 31

Selective medium

Question 32

What is a popular liquid medium in bacteriology laboratories; it supports the growth of all categories of bacteria from obligate aerobes to obligate anaerobes?

Answer 32

Thioglycollate (THIO) broth

Question 33

What involves adding a portion of a specimen to the medium?

Answer 33

Inoculation

Question 34

Unwanted organisms are referred to as?

Answer 34

Contaminants

Question 35

After media are inoculated, they must be placed into an ________ which will maintain the appropriate atmosphere, temperature, and moisture level.

Answer 35

Incubator

Question 36

What are the 3 types of incubators used in clinical microbiology laboratories?

Answer 36

- CO2 incubator - non-CO2 incubator - anaerobic incubator

Question 37

What can be used to determine growth by measuring the turbidity of the medium?

Answer 37

spectrophotometer

Question 38

What is used to determine the number of viable bacteria in a liquid sample by making serial dilutions of the liquid and inoculating onto nutrient agar; after overnight incubation, the number of colonies is counted?

Answer 38

viable plate count

Question 39

TRUE/FALSE: A population growth curve for any particular species of bacterium may be determined by growing a pure culture of the organism in a liquid medium at a constant temperature.

Answer 39

TRUE

Question 40

What is prepared by plotting the logarithmic number of viable organisms against the incubation time?

Answer 40

Graph

Question 41

**Obligate intracellular pathogens** are microbes that can survive and multiply only within?

Answer 41

Host cells

Question 42

What is the complete destruction of all microbes, including cells, spores, and viruses?

Answer 42

Sterilization

Question 43

What is the destruction or removal of pathogens from nonliving objects by physical or chemical methods?

Answer 43

Disinfection

Question 44

What are chemical substances that eliminate pathogens on inanimate objects?

Answer 44

Disinfectants

Question 45

What are solutions used to disinfect skin and other living tissues?

Answer 45

Antiseptics

Question 46

TRUE/FALSE Bactericidal agents are chemicals that specifically kill bacteria, but not necessarily bacterial endospores.

Answer 46

TRUE

Question 47

What is a drug or chemical that inhibits growth and reproduction of microbes?

Answer 47

microbistatic agent

Question 48

What drug is one that specifically inhibits the metabolism and reproduction of bacteria?

Answer 48

bacteriostatic agent

Question 49

What is a process that combines dehydration (drying) and freezing? This process is widely used in industry to preserve foods, antibiotics, microorganisms, and other biologic materials

Answer 49

Lyophilization

Question 50

What refers to the presence of pathogens in blood or tissues, whereas asepsis means the absence of pathogens?

Answer 50

Sepsis

Question 51

What is the prevention of infection?

Answer 51

Antisepsis

Question 52

What factors determine the effectiveness of heat for sterilization?

Answer 52

- Temperature - Time

Question 53

What is a large metal pressure cooker that uses steam under pressure to completely destroy all microbial life?

Answer 53

Autoclave

Question 54

What do you call the process when many dried microorganisms remain viable, but they cannot reproduce?

Answer 54

Desiccation

Question 55

What is used in hospitals and medical and dental clinics to clean equipment?

Answer 55

Ultrasonic waves

Question 56

What refers to the use of chemical agents to inhibit the growth of pathogens, either temporarily or permanently?

Answer 56

Chemical disinfection