Monera Flashcards
1
Q
General characteristics of Monera
A
- single-celled
- Prokaryotic
- Microscopic
- Carry out respiration
- Binary fission
- Have ribosomes
- Role: Decomposition of dead organisms
- Found everywhere
2
Q
Name the shapes of Monera
A
- Coccus/Round
- eg: Streptococcus- causes septic throat - Rods
- eg: Coli- in the colon - Spirals
- eg: Cholera
3
Q
What are the benefits of bacteria
A
- Production of yoghurt and cheese
- Manufacturing antibiotics
- Insulin production
- Nutrient recycling
4
Q
Harmful effects of bacteria
A
- Can cause disease (Animal- food poisoning Plant- rot)
- Food spoilage (Milk turns sour)
- Tooth decay (Enamel)
5
Q
Bacterial cell structure
A
Always present: - Cell wall - Cell membrane - Cytoplasm - Ribosome - Storage granule - Loop of DNA Sometimes present: - Capsule - Flagella - Plasmid
6
Q
Role of Cell wall in Bacteria
A
- prevents cell from bursting
7
Q
Role of Cell membrane in Bacteria
A
- Selectively permeable
8
Q
Role of Cytoplasm in Bacteria
A
- Suspends ribosomes and storage granules
9
Q
Role of Plasmid in Bacteria
A
- Cloning vector
- Bacterial resistance
10
Q
Role of capsule
A
- Protects from drying out
11
Q
Role of Flagellum
A
- Used for movement in search of food
12
Q
How does Monera carry out sexual reproduction?
A
Binary fission
13
Q
Briefly explain how binary fission occurs
A
- DNA replicates
- Cell elongates
- DNA copies move to opposite sides of the cell
- Ingrowth of membrane occurs
- Cytoplasm divides to form two daughter cells
- Bacteria produce themselves every 20 minutes
- leads to create clones (identical daughter cells)
14
Q
Important consequences of bacterial reproduction
A
- Wounds become heavily infected very quickly
- Appear in large numbers
- Can transfer plasmids and antibiotic resistance
- Efficient returns of product in industry
15
Q
Define Endospore
A
- unicellular resistant structure produced during harsh conditions
16
Q
Steps in endospore formation
A
- DNA replicates
- Cytoplasm shrinks
- DNA is surrounded by a thick cell wall
- Outer cell breaks down
- Endospores remain dominant for decades
17
Q
When conditions are suitable again
A
- Endospore absorbs water
- Spore wall softens and ruptures
- A new bacterial cell emerges, enlarges and reproduces by binary fission
18
Q
What is meant by autotrophic?
A
Make their own food
19
Q
Define Photosynthetic and give an example
A
Use light to make food
eg: Purple sulphur bacteria
20
Q
Define Chemosynthetic
A
Use energy from chemical reactions
eg: Nitrifying bacteria
21
Q
What is meant by Heterotrophic?
A
Take in food from other organisms
22
Q
Define saprophytic and give an example
A
feed on dead organic matter
eg: bacteria of decay
23
Q
Define parasitic and give an example
A
Feed on living host causing it harm
eg: streptococcus
24
Q
Define Pathogen
A
Disease-causing agent
25
Define Antibiotic
Chemicals produced by micro-organisms to kill other micro-organisms
26
Role of antibiotics
Treat bacterial or fungal infections
27
What is meant by antibiotic resistance?
Bacterial or fungi are not killed by the antibiotic
28
How does antibiotic resistance develop
Misuse of antibiotics, using antibiotics to treat viral infections
29
How does resistance develop
- all bacteria are killed (good and bad)
- bacteria will have no competition
- Can increase in numbers rapidly
- Antibiotics will not affect it
- MRSA is a bacterial strain resistant to most antibiotics and is more common in hospitals
30
Abuse of antibiotics in medicine
- Using antibiotics to treat viral infections
- Patients failing to complete their full course of antibiotics
- Using a broad-spectrum antibiotic that inhibits many bacteria
31
Doctors are reluctant to prescribe antibiotics to patients with common cold-like symptoms. Suggest a biological reason for this statement.
- Common cold can be viral
| - Antibiotics have no effect on viruses
32
Factors affecting growth
1. Temperature
2. Oxygen concentration (Anaerobic facultative can respire without oxygen) (Obligate anaerobes respire in absence of oxygen)
3. pH
4. External solute concentration
5. Pressure
33
List the stages of the bacterial growth curve
1. Lag
2. Log
3. Stationary
4. Death/Decline
5. Survival
34
Briefly describe the phases of the bacterial growth curve
1. Lag phase: Bacteria numbers are low-Adapting to their new environment
2. Log phase: Bacteria numbers increase rapidly- plenty of food, oxygen, moisture
3. Stationary phase: Number remains high and constant- Reproduction rate=death rate
4. Decline phase: Bacteria decrease in numbers (death rate is greater than reproduction rate)
5. Survival phase: Bacteria survive as endospores
35
Define Bioprocessing
- Use of micro-organisms to produce food and other products
| - Micro-organisms grow in a liquid medium in a bioreactor
36
Give a brief account of batch processing and give an example
Example: Antibiotics
Describe: Fixed amount of sterile nutrients are added to --the bioreactor at the start
-Go through all stages of growth
-Bioreactor is emptied and the product extracted at the end
37
Give advantages and disadvantages of batch processing
Advantages:
- Easier process to control
- Useful when products may be needed only in small amounts
- Some micro-organisms grow well for a short period of time
Disadvantages:
- Product not available at short notice
- Sterilising the bioreactor takes a lot of time
38
What is meant by Continuous flow processing? Briefly describe and give an example
Definition: Nutrients are continuously added to the bioreactor
Example: Single-celled protein
- Microorganism growth maintained at the upper log phase
- Products are continuously removed
-
39
Give advantages and disadvantages of continuous flow food processing
Advantage: Quicker process
Disadvantage: Requires close monitoring
40
Give one example of a beneficial effect of bacteria, other than the production of antibiotics and one example of a harmful effect of bacteria
Beneficial effect: Nutrient recycling
| Harmful effect: Cause disease
41
Name a method of asexual reproduction
Binary fission
42
Describe the process of asexual reproduction
- DNA replicates
- Cell elongates
- DNA copies and moves to opposite sides
- Ingrowth of membrane
- Cytoplasm divides to form two identical daughter cells
43
How do certain bacteria survive when environmental conditions become unfavourable?
Formation of endospore
44
Name 3 general shapes of bacterial cells
Rod, Cocci, Spiral
45
What is the difference between asepsis and sterility
Asepsis: Free of pathogens
Sterility: Free of micro-organisms
46
Give one way in which bacteria cope with unfavourable environments
Endospores
47
Distinguish between Batch processing and Continous flow
Batch processing: a fixed amount of nutritions added at the beginning
Continuous flow: Nutrients continuously fed into the bioreactor
48
Explain what is happening at the stationary phase
Stationary phase: Bacteria Number remains high and constant
- Reproduction rate=death rate
- Limited space and food
49
Other than being prokaryotic state two ways in which a typical bacterial cell differs from a typical human cell
- Cell wall
| - Size
50
Misuse of antibiotics
- survival of resistant strains
51
Name two forms of heterotrophic nutrition
1. Parasitic
| 2. Saprophytic
