Growth of Microbes

Question 1

Factors that affect the growth of microbes

Answer 1

Availability of nutrients
Moisturise
Temperature
pH
Osmotic pressure
Atmospheric pressure
Gaseous environment (Aerobes and anaerobes)

Question 2

Why we grow microbes

Answer 2

To isolate and identify microorganisms from clinical specimens that might contain pathogens
To learn more about different microbes
To produce certain food and beverages

Question 3

Generation time

Answer 3

Time it takes for one cell to divide into two cells (population = double)

Question 4

Media

Answer 4

A substance used to grow bacteria

it is artificial as doesn’t occur naturally

Question 5

Agar plate

Answer 5

A petri dish that contains agar as a solid growth medium plus nutrients
Used to culture microorganisms

Question 6

Selective media

Answer 6

A media that discourages the growth of some organisms while not affecting the growth of other organisms

Question 7

Differential media

Answer 7

Media that allows you to differentiate between different types of organisms that are all growing on the media

Question 8

Sterilisation

Answer 8

The destruction/elimination of all microbes

Question 9

Physical methods of Sterilisation

Answer 9

Dry heat (ovens
Moist heat (Autoclaves)
Gamma irrigation
Filtration

Question 10

Chemical agents of sterilisation

Answer 10

Ethylene oxide

Glutaraldehyde

Question 11

Disinfection

Answer 11

The elimination of most or all pathogens (except endospores) from non-living objects

Question 12

Physical methods of disinfection

Answer 12

Boiling
Pasteurisation
UV radiation

Question 13

Chemical agents of disinfection

Answer 13

Alcohols
Halogens
Phenols
Heavy metals
Aldehydes

Question 14

Sanitation

Answer 14

The reduction of microbial populations to levels that are considered safe by public health standards

Question 15

Physical methods of sanitation

Answer 15

Heat - boiling, burning, pasteurisation, autoclave
Desiccation - Drying
Radiation - Gamma radiation and UV light
Filtration
Cleaning - hand washing (mechanical removal)

Question 16

Disinfectants

Answer 16

Chemicals that are used to kill microbes on inanimate objects

Question 17

Antispetics

Answer 17

Chemicals that are used to disinfect skin and other living tissues

Question 18

Microbicidal agents

Answer 18

Chemicals that kill microbes

e.g disinfectants and antispectics

Question 19

Classes of microbicidal agents

Answer 19

Bactericidal agents
Sporicidal agents
Fungicidal agents
Viricidal agents

Question 20

Microbistatic agents

Answer 20

Substances that inhibit the growth of microbes but do not necessarily kill them

Question 21

Sepsis

Answer 21

The presence of pathogens in the blood or tissue

Question 22

Asepsis

Answer 22

The absence of pathogens

Question 23

Aseptic techniques

Answer 23

A collection of techniques that are used to prevent contamination by eliminating and excluding pathogens

Question 24

Sterile techniques

Answer 24

Techniques that are used to eliminate all microbes from a particular area