Microbiology

Question 1

What is microbiology

Answer 1

The study of microorganisms

Question 2

Classification of microorganisms

Answer 2

Fungi
Bacteria
Viruses

Question 3

Conditions needed for the growth of microorganisms

Answer 3

Food (saprophytic and parasitic)
Oxygen (aerobic, anaerobic and facultative)
Temperature
Moisture
Ph level 
Time

Question 4

What are saprophytic microorganisms

Answer 4

They feed on non living matter eg decaying plants

Question 5

What are parasitic microorganism

Answer 5

They feed on living matter eg animals/human

Question 6

What are aerobic microorganisms

Answer 6

Require oxygen

Question 7

What are anaerobic microorganisms

Answer 7

Don’t require oxygen

Question 8

What are facultative microorganisms

Answer 8

Can grow with or without oxygen

Question 9

Microorganisms grow on foods with what water activity

Answer 9

0.80 or higher

Question 10

Thermophilic means

Answer 10

Very hot environment

Question 11

Examples of saprophytic fungi

Answer 11

Mushrooms

Mould

Question 12

Examples of parasitic fungi

Answer 12

Ring worm,

Athletes foot

Question 13

Use of mould

Answer 13

Manufacture of food stuff eg. Cheese

Manufacture of medicine eg penicillin

Question 14

Conditions needed for the growth of mould

Answer 14

Food (they’re saprophytic)
Oxygen (they’re aerobic so will grow on the surface of foods)
Temperature (mesophilic (medium), they slow down at lower temperatures and are destroyed at higher temperatures)
Moisture (humid is best)
Ph (slightly acidic)
Time (24-48 hours)

Question 15

How many cells in a mould spore

Answer 15

1

Question 16

Cycle of mould

Answer 16

Spore
Grows hypha 
Once in right condition grows hyphae 
Hyphae all become intertwined into mycelium 
Hyphae grow upwards from mycelium

Question 17

Does mould sexually or asexually reproduce

Answer 17

Both

Question 18

Tow types of moulds

Answer 18

Phycomycetes

Ascomycetes

Question 19

Example of large fungi

Answer 19

Mushrooms

Question 20

Poisonous mushroom

Answer 20

Death cap

Question 21

Alright mushroom

Answer 21

Truffle

Question 22

Reproduction of mushrooms

Answer 22

Start as single spore
Hyphae grow
Mycelium form
Hyphae bunch up and grow upwards into a stalk
Cap forms at top
Underside has gills
When ripe, mushrooms release spores
Spores are dispersed

Question 23

Conditions needed for the growth of yeast

Answer 23

Food; saprophytic 
Oxygen; facultative
Temperature; mesophilic 
Moisture 
Ph level; slightly acidic (4-6)
Time

Question 24

Reproduction of yeast name

Answer 24

Asexually

Budding

Question 25

Explain budding

Answer 25

When conditions are favourable, parent cell develops bud Nucleus splits in two and moves towards bud One goes into bud Cell wall develops 2 separate now Many buds will produce

Question 26

Advantages of fungi

Answer 26

``` Protein;alternative foods Edible Cheese production Antibiotics Bread and brewing Vitamin supplements ```

Question 27

Disadvantages of fungi

Answer 27

Food spoilage Poisonous Human diseases Animal disease

Question 28

Conditions needed for growth of bacteria

Answer 28

Food: both saprophytic and parasitic Oxygen: aerobic, anaerobic and facultative Temperature:all 4 Moisture Ph: 6-7 (extreme heats or ph inhibits growth) Time (double every 20 mins)

Question 29

How do bacteria reproduce

Answer 29

Binary fission

Question 30

Explain binary fission

Answer 30

``` Cell elongates Nucleus splits in two Spread apart Wall forms Two new cells ```

Question 31

Stages in bacteria growth

Answer 31

Lag phase Log phase Stationary phase Decline phase

Question 32

What happens in lag phase

Answer 32

Little growth of bacteria as they are adapting to their environment

Question 33

What happens in log phase

Answer 33

Bacteria multiply quickly as are in ideal conditions

Question 34

What happens in stationary phase

Answer 34

No increase in growth Production of new bacteria is compensated for by death of other bacteria Plateau Reason for death: lack of food, space and oxygen causes competition

Question 35

Decline phase

Answer 35

Greater amount dying than being produced. | Some survive by producing endospores

Question 36

What are endospores

Answer 36

Tough, dormant cells that form around DNA of a bacterial cell to suirvue

Question 37

How to endospores form

Answer 37

DNA duplicates Endospore forms around one Rest of cell disintegrates and endospore remains dormant Reproduce by binary fission when in suitable conditions

Question 38

Example of endotoxins

Answer 38

Salmonella

Question 39

Example of exotoxins

Answer 39

Staphylococcus aureus

Question 40

Shapes of bacteria

Answer 40

Coccus (round) eg pneumonia Bacillus (rod) eg salmonella Curved and spiral eg cholera

Question 41

Gram positive stain

Answer 41

Purple

Question 42

Gran negative stain

Answer 42

Pink

Question 43

Two ways of classifying bacteria

Answer 43

Shape | Gram staining

Question 44

Features of a gram positive cells

Answer 44

Thick cell wall No flagella Produces spores Low resistance to antibiotics

Question 45

Example of a gram positive

Answer 45

Streptococci

Question 46

Gram negative features

Answer 46

2 thin layers Flagella No spore production High resistance to antibiotics

Question 47

Example of gram negative

Answer 47

E. coli