UNIT 3: Kingdom Monera

Question 1

Bacteria

Answer 1

Ubiquitous
Most numerous living organism on earth.
Prokaryotes - no membrane bound organelles

Question 2

Structure of bacteria

Answer 2

Have a cell wall and cell membrane, but no organelles.

Many bacteria have an additional layer of protection called the capsule and flagella (for movement)

Question 3

Capsule

Answer 3

Slime layer for protection

Question 4

Cell wall

Answer 4

Structure and protection

Question 5

Cell membrane

Answer 5

Selectively permeable controlling what enters and leaves the cell

Question 6

Flagellum

Answer 6

Movement

Question 7

Chromosome

Answer 7

DNA and protein carrying genes

Question 8

Ribosome

Answer 8

Protein synthesis

Question 9

Cytoplasm

Answer 9

Liquid portion of the cell in which all metabolic reactions occur

Question 10

Plasmid

Answer 10

Circular piece of DNA that gives the bacterium special traits such as antibiotic resistance

Question 11

Spherical bacteria

Answer 11

Round and spherical in shape e.g. staphylococcus aureus (bacterium normally present on human skin)

Question 12

Spiral bacteria

Answer 12

Spiral or helical shape e.g. helicobacter pylori (bacterium that often causes stomach ulcers)

Question 13

Rod bacteria

Answer 13

Elongated rod shape e.g. lactobacillus casei (bacterium found in milk)

Question 14

Bacterial reproduction

Answer 14

Bacteria reproduce by binary fission

Question 15

Binary fission

Answer 15

Asexual reproduction in bacteria

Question 16

Endospore

Answer 16

Thick, tough-walled, dormant and dehydrated bacterial cell formed during unsuitable conditions

Question 17

Process of endospore formation

Answer 17

• conditions become unfavourable for the bacterial cell.
• cell undergoes asymmetrical binary fission with the smaller cell being engulfed by the larger cell.
• thick wall, called the cortex, forms around the engulfed cell.
• outer coat forms around the cortex

Question 18

Nutrition in bacteria

Answer 18

Nutrition - way in which organisms obtain and use food

1. Autotrophic
2. Heterotrophic

Question 19

Autotrophic nutrition

Answer 19

Way in which organisms make their own food.

Question 20

Autotrophic nutrition (chemosynthetic nutrition)

Answer 20

Way in which bacteria make their own food from inorganic chemicals e.g. nitrifying bacteria produce nitrates (used in protein synthesis) from ammonia.

Question 21

Autotrophic nutrition (photosynthetic nutrition)

Answer 21

Way in which bacteria use sunlight to make their own food e.g. purple sulphur bacteria produce carbohydrates from carbon dioxide using light energy

Question 22

Heterotrophic nutrition

Answer 22

Way in which organisms obtain their food from other organisms

Question 23

Heterotrophic nutrition (saprophytic nutrition)

Answer 23

Way in which bacteria feed off dead organic matter e.g. bacteria of decay

Question 24

Heterotrophic nutrition (parasitic nutrition)

Answer 24

Way in which bacteria feed directly off living organisms e.g. E.Coli

Question 25

Factors effecting bacterial growth

Answer 25

``` Temperature Oxygen concentration Ph External solute concentrations Pressure ```

Question 26

Temperature

Answer 26

Lower temperatures mean lower enzyme activity and a much slower rate of bacterial binary fission

Question 27

Oxygen concentration

Answer 27

Most bacteria need oxygen to survive (aerobic bacteria). - There are bacteria that are killed by oxygen called obligate anaerobic bacteria. - There are bacteria that cannot use oxygen but tolerate its presence called aero tolerant anaerobic bacteria. - There are bacteria that can use oxygen but do not depend on it called facultative anaerobic bacteria.

Question 28

pH

Answer 28

Changes in pH effect enzyme function meaning pH values outside of optimum mean that certain bacteria cannot survive. Most bacteria require a neutral pH. There are bacteria that can survive in very acidic conditions called acidophiles. There are bacteria that can survive in very alkaline conditions called alkaliphiles.

Question 29

External solute concentrations

Answer 29

The concentrations of the solution surrounding the cell effects the rate of osmosis. If osmosis occurs too quickly in either direction (in or out of the cell) then the cell may die

Question 30

Pressure

Answer 30

Fluid pressure effects all living organisms. High pressures are used by many companies in the food industry to sterilise (kill micro organisms) the food. High pressure kills microorganisms by breaking the cell wall and cell membranes

Question 31

Growth curve of microorganisms

Answer 31

1. Lab phase 2. Log phase 3. Stationary phase 4. Decline phase 5. Survival phase

Question 32

Lag phase

Answer 32

Microorganisms are adjusting to a newly colonised environment

Question 33

Log phase

Answer 33

Microorganisms start to reproduce exponentially

Question 34

Stationary phase

Answer 34

Nutrients begin to run out / toxins begin to build up causing reproduction to slow down and death to increase

Question 35

Decline phase

Answer 35

Death of microorganisms is at a higher rate than reproduction due to build up in toxins

Question 36

Survival phase

Answer 36

Some microorganisms produce endospores and can survive the harsh conditions

Question 37

Beneficial bacteria

Answer 37

Lactic acid bacteria | E. Coli

Question 38

Lactic acid bacteria

Answer 38

Bacteria found in dairy products that help in the production of many diary products. They also colonise our digestive systems producing lactic acid and inhibiting the growth of harmful bacteria

Question 39

E Coli

Answer 39

Bacteria of the large intestine are responsible for producing vitamins

Question 40

Harmful bacteria

Answer 40

Strep throat bacteria | Tuberculosis bacteria

Question 41

Strep throat bacteria

Answer 41

Cause of sore throat and scarlet fever

Question 42

Tuberculosis bacteria

Answer 42

Cause of tuberculosis

Question 43

Antibiotics

Answer 43

Chemicals produced by microorganisms that inhibit the growth of, or kill, other microorganisms without damaging human tissue

Question 44

Overuse of antibiotics

Answer 44

Has led to the emergence of emergence of antibiotic resistance among bacteria strains such as MRSA. Resistance to antibiotics occurs when one bacterium in a population develops a mutation that enables it to avoid the effects of the antibiotics. This one bacterium then divides to form a new colony of resistant bacteria that are unaffected by the antibiotic

Question 45

Food processing

Answer 45

Taking raw ingredients and converting them to food fit for consumption