Micro-organisms

Question 1

What are micro-organisms?

Answer 1

Living organisms that aren’t directly visible to the unaided eye.

Question 2

What are the 3 types of micro-organisms?

Answer 2

1. Bio (life)
2. Micro (small)
3. Logy (study of)

Question 3

Where are micro-organisms found?

Answer 3

Air, soil, water, animals, human body.

Question 4

Where are micro-organisms found?

Answer 4

Air, soil, water, animals, human body.

Question 5

What is the definition of bacteria?

Answer 5

Microscopic, single celled organism.

Question 6

What do bacteria need for growth?

Answer 6

Moisture

Question 7

What can bacteria cause?

Answer 7

Food-bourne illnesses.

Question 8

What are the 3 basic shapes of bacteria?

Answer 8

1. Bacillus (rod)
2. Coccus (spherical)
3. Spiral (spirullum)

Question 9

What is the function of bacteria?

Answer 9

Form structures (Spores) to protect themselves from adverse conditions.

Question 10

What happens when conditions are favourable?

Answer 10

They burst out, grow and multiply through Binary Fission.

Question 11

What is Fungi?

Answer 11

Single-celled organism, seen as only individual cells under microscope.

Question 12

Do fungi require more/less moisture?

Answer 12

Less due to being able to grow in acidic environments.

Question 13

Do fungi form spores?

Answer 13

Some can but overall they are less resistant.

Question 14

Do fungi grow quicker/slower?

Answer 14

Slower but very adaptable.

Question 15

What are the fungi groups?

Answer 15

1. Zygomycetes
2. Ascomycetes
3. Basidiomycetes
4. Deutromycetes

Question 16

What is it called when cocci remain in pairs?

Answer 16

Diploccoci

Question 17

What is it called when cocci remain in chains?

Answer 17

Streptococci

Question 18

What is it called when cocci that have divided into pairs and remain in groups of 4?

Answer 18

Tetrads

Question 19

What shape do bacilli mainly appear as?

Answer 19

single rods known as Diplobacci

Question 20

What shape do sprial have usually?

Answer 20

Curved rods known as Vibrios.

Question 21

What is the definition of growth?

Answer 21

Process by which micro-organisms synthesise vital cell components.

Question 22

What are the vital cell components that are synthesised?

Answer 22

1. Cell wall material
2. Cytoplasmic material
3. Genetic material

Question 23

What is generation time?

Answer 23

The time it takes for the population of bacteria to double in numbers.

Question 24

What are the 4 different growth phases of bacteria?

Answer 24

1. Lag phase
2. Log phase
3. Stationary phase
4. Death phase

Question 25

What happens in the Lag phase?

Answer 25

1. Bacteria introduced into environment - checking surroundings
2. Cells are very active metabolically
3. Some cells change very little
4. 1 hour - 7 days

Question 26

What happens in the log phase?

Answer 26

1. Rapid cell growth
2. Populations double every generation
3. Microbes = sensitive to adverse conditions

Question 27

What happens during the stationary phase?

Answer 27

1. Death rate = rate of production

2. Cells start to encounter environmental stress

Question 28

What happens in the death phase?

Answer 28

1. Death rate greater than rate of reproduction

2. Populations begin to die

Question 29

What are some of the intrinsic factors that affect growth of bacteria?

Answer 29

1. pH
2. Moisture
3. Nutrient content

Question 30

What are some of the extrinsic factors that affect growth of bacteria?

Answer 30

1. Temperature
2. Relative humidity
3. Gaseous environment

Question 31

What pH can no pathogen grow under?

Answer 31

pH of below 4.6