monera

Question 1

Cell wall

Answer 1

shape & structure. Made of sugars and proteins. Prevent cell taking in too much liquid when surrounded by less concentrated solution.

Question 2

Cell membrane

Answer 2

holds all cell contents, controls what enters and leaves the cell. Semi-permeable, lipo-protein layer.

Question 3

Cytoplasm

Answer 3

contains ribosomes and storage

granules but no mitochondria or

chloroplasts.

Question 4

Flagellum

Answer 4

for movement.

Question 5

Capsule

Answer 5

a semi-solid layer of mucilage that protects.

Question 6

Nuclear material

Answer 6

DNA material

Question 7

What are the shapes of bacteria

Answer 7

1. Spherical (cocci)
2. Rod (bacillus)
3. Spiral (spirillum)

Question 8

What is binary fission

Answer 8

A reproduction method which is a fast replication of cells. This means all daughter cells are identical

Question 9

Explain binary fission

Answer 9

The chromosome attaches to the plasma membrane and the DNA is replicated The cell elongates and the two chromosomes separate The cell wall grows to divide the cell into two two identical daughter cells are formed

Question 10

Endospore formation

Answer 10

A way that bacteria can withstand unfavorable conditions

Question 11

Explain endospore formation

Answer 11

These are formed when the bacterial chromosome replicates The parent cell then breaks down and the endospore remains dormant One of the new strands becomes enclosed in a tough-walled capsule called an endospore The parent cell then breaks down and the endospore remains dormant When conditions are favourable the spores absorb water, break their walls and reproduce by binary fission

Question 12

Autotrophic bacteria

Answer 12

Make their own food

Question 13

Photosynthetic bacteria

Answer 13

Use light energy to make food

Called producers

E.g. purple sulphur bacteria

Question 14

Chemosynthetic bacteria

Answer 14

Use energy from chemical reactions to make food

E.g. Nitrifying bacteria that convert ammonia to nitrates in the nitrogen cycle

Question 15

Heterotrophic

Answer 15

Feed on other organisms

Question 16

3 types of heterotrophic bacteria

Answer 16

Soprophytes
Parasites
Symbiotes

Question 17

Soprophytes

Answer 17

Feed on dead matter causing it to breakdown and this allows nutrients to be recycle.

Question 18

Parasites

Answer 18

Live on or in a host and take nutrients from it but the host is harmed in the process.

Question 19

Symbiotes

Answer 19

Live in close union with other organisms to each other’s benefit. E.g. symbiotic bacteria in the human intestine

Question 20

Factors affecting growth of bacteria

Answer 20

Temperature

Oxygen concentration

pH

External solute concentrat

Pressure

Question 21

Temperature

Answer 21

Most grow between 20°C to 30°C
Low temperatures = slow growth
Some can tolerate higher temperatures without their enzymes becoming denatured

Question 22

Ph

Answer 22

Most live at 7-8 ph (alkaline)
Few can tolerate acidic/very alkaline conditions
Not suitable ph =enzymes denatured

Question 23

Oxygen

Answer 23

For respiration (aerobic bacteria)
Facultative anaerobes can respire with or without oxygen
Obligate anaerobes can only respire in the absence of oxygen

Question 24

External solute concentration

Answer 24

Osmosis.
If external solution is more concentrated water will move out of the bacteria(dehydration)
If external solution is less concentrated water will enter the bacteria

Question 25

Pressure

Answer 25

The growth of bacteria is inhibited by high pressures

Question 26

Beneficial bacteria

Answer 26

Lactobacillus converts milk to yoghurt and cheese

Antibiotics can be formed by some microorganisms

Question 27

Harmful bacteria

Answer 27

Pathogenic Bacteria can cause diseases in humans and animals.

Pathogenic Bacteria can cause diseases in plants.

Question 28

Pathogenic

Answer 28

Micro-organisims that cause diseases

Question 29

Antibiotics uses

Answer 29

Control bacteria and fungal infections without affecting the virus

Question 30

Abuse of antibiotics

Answer 30

Increase growth of antibiotic resistant bacteria

Question 31

Mutation in bacteria

Answer 31

Causes bacteria to develop antibiotic resistance

Question 32

Growth curve bacteria

Answer 32

The lag phase
The log phase
The stationary phase
Decline phase
Death or survival phase

Question 33

Lag phase

Answer 33

‘Settling In’ phase, bacteria adjust to their new environment.

Question 34

Log phase

Answer 34

Also known as exponential phase, bacteria begin to divide very rapidly.

Question 35

The stationary phase

Answer 35

There is no increase or decrease in numbers. The no. dead equals the no. created.

Question 36

Decline phase

Answer 36

Numbers drop because there is increased competition for food, space and oxygen. There is a buildup of toxins and waste in the environment.

Question 37

Death or survival phase

Answer 37

Not all bacteria die, some may survive in spores until good conditions return

Question 38

Batch culture

Answer 38

The bacteria in the bioreactor go through the lag, log and stationary phases but stopped before the decline phase. The contents of the bioreactor are then removed and separated.

Question 39

Continues flow culture

Answer 39

The bacteria are constantly kept in log phase. Nutrients are constantly fed in and culture medium are fed out. All factors have to be kept constant. Used in waste water treatment and production of single cell proteins.

Question 40

Advantages of batch culture

Answer 40

Easier to control

Product may only be needed in small amounts

O Product may only be needed at certain

times

Bacteria grow better in batch culture

Question 41

Disadvantage of batch culture

Answer 41

Low productivity

Question 42

Disadvantages of continous dlow

Answer 42

increase the risk of contamination of materials

Question 43

Advantage of continous flow

Answer 43

Higher volume production. Smaller storage space.