Biology > Bacteria > Flashcards

Bacteria Flashcards

(67 cards)

Study These Flashcards
1
Q

What are the three shapes of bacteria and examples of each

A
  • Round e.g. sore throat
  • Rod e.g. TB
  • Spiral e.g. syphilis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How are bacteria classified?

A

According to shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the purpose of the cell membrane?

A

Controls what enters and leaves the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define limiting factor

A

A factor that slows down a process when in short supply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define antibiotic

A

A chemical made from a bacteria or fungus to kill a bacteria or fungal disease. Does not kill viruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define endosperm

A

Food store in plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Draw a diagram to show binary fission

A

N/A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the purpose of the mesosome?

A

Folding, increases surface area for respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain how external solute concentration affects the growth of bacteria

A
  • Bacteria gain or lose water by osmosis
  • If ESC is higher than bacteria cytoplasm, water will move out of bacteria which causes them to stop working e.g. salting and sugaring food
  • If ESC is lower bacteria will gain water. Cell walls prevent bacteria from bursting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name factors affecting the growth of bacteria

A
  • Temperature
  • Oxygen concentration
  • External solute concentration
  • Pressure
  • pH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Do bacteria produce sexually or asexually?

A

Asexually - offspring is a genetically identical clone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain how pH affects the growth of bacteria

A
  • Unsuitable pH can cause the enzymes in bacteria to be denatured.
  • Optimum is 7
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the function of the flagella?

A

Movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do bacteria evolve?

A
  • Mutations - change in structure of DNA
  • Short life cycle - variations (mutations) are passed on quickly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the disadvantages of bacteria?

A
  • Cause disease e.g. TB, food poisoning
  • Pathogenic bacteria cause food to decay e.g. milk turn sour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the function of the ribosome?

A

Makes protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the purpose of the cell wall?

A

Protection/support of cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens to the endospores under favourable conditions?

A

The spores absorb water, break their walls and reproduce by binary fission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Draw and label diagram of a bacterial cell, distinguishing between sometimes present and always present organelles

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the function of endospores

A

To withstand unfavourable conditions and aid dispersal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Give an example of saprophytic bacteria

A

Bacteria of decay in the soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Give an example of parasitic bacteria

A

TB, salmonella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Explain how pressure affects the growth of bacteria

A
  • Growth is stopped by high pressure
  • Walls are not strong enough to withstand the high pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the bacteria’s life cycle like?

A

Short life cycle - variations (mutations) are passed on quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What do humans do to cause antibiotic resistance?
* Overuse of antibiotics * Failure to complete a full treatment of antibiotics
26
How do bacteria evolve resistance to new antibiotics?
* Mutations – change in structure of DNA * Short life cycle – variations (mutations) are passed on quickly
27
What is the plasmid?
Loop of DNA.
28
Give an example of photosynthetic bacteria
Purple sulfur bacteria
29
Are bacterial cells prokaryotic or eukaryotic
Prokaryotic
30
What are two different ways autotrophic bacteria get nutrition?
Photosynthetic bacteria - Make food using light. Have chlorophyll Chemosynthetic bacteria - Make food using chemicals/chemical reactions
31
What are two different ways heterotrophic bacteria get nutrition?
Saprophytic - Lives off dead decaying matter Parasitic - Lives off a live host causing harm
32
Where are zygospores found
In fungi
33
What is the name for bacterial reproduction?
Binary fission
34
What is the purpose of the capsule?
Protection
35
How do bacteria/fungi develop antibiotic resistance?
* Developed from mutations - change in the structure of the DNA * Natural selection occurs and resistant strains multiply
36
Define prokaryotic
No nucleus or membrane-bound organelles
37
What are the benefits of bacteria?
* Used to make cheese and yoghurt e.g. lactobacillus * Preserves silage * Makes antibiotics * Decomposers
38
Draw a diagram to show endospore formation
N/A
39
Give an example of chemosynthetic bacteria
Nitrifying bacteria
40
Define pathogen
Disease-causing microorganism
41
What kingdom do bacteria belong to?
Monera
42
Describe the process of binary fission
* DNA strand replicates * Two identical strands * Cell elongates * DNA moves to either end * Ingrowth of membrane (or walls) * Cell splits into two similar sized genetically identical cells
43
Explain how temperature affects the growth of bacteria
- Optimum is 20–30º - Boiling causes some bacteria's enzymes to be denatured - Freezing conditions cause decreased growth
44
What are some differences between bacterial cells and animal cells?
Bacterial cells have cell walls, capsules, flagellum and plasmids. They are different sizes
45
Explain how oxygen concentration affects the growth of bacteria
- Aerobic bacteria: requires oxygen - Anaerobic bacteria : do not require oxygen Facultative: Can respire with/without oxygen Obligate: Can only respire without oxygen
46
How do bacteria evolve?
* Mutations – change in structure of DNA * Short life cycle – variations (mutations) are passed on quickly
47
How and when do endospores form?
Under harsh conditions DNA replicates, a thick wall encloses one of the DNA, the cell cytoplasm loses water and shrinks
48
Who discovered the first antibiotic?
Sir Alexander Fleming
49
What cell organelles are absent from a bacterial cell?
Mitochondria, chloroplast and nucleus
50
Define antibiotic resistance
Bacteria/fungus that are not killed by antibiotics
51
What is the purpose of the cytoplasm?
Liquid part of the cell, holds contents of cell in place
52
Define endospore
A thick coat within the original structure
53
How do bacteria evolve resistance to new antibiotics?
* Mutations - change in structure of DNA * Short life cycle - variations (mutations are passed on quickly)
54
Where is the gene for antibiotic resistance found in bacteria?
Plasmid
55
Define pathogenic
Disease-causing
56
Describe the growth in populations of bacteria
* Lag: Bacteria are adapting to their environment * Log: Bacteria population are increasing rapidly due to plenty food, space, oxygen, moisture * Stationary: Number dying = number of new bacteria. Slows down due to lack of food, space, moisture, oxygen. Toxins build up. * Decline: Number dying is greater than being produced * Death or survival: Some bacteria survive as spores until suitable conditions arise again
57
Draw and label diagram to illustrate growth of bacteria
N/A
58
Define single cell protein
Use of bacteria to produce edible forms of protein
59
Where do biological reactions occur?
Bioreactors
60
Define bioreactors
Vessels in which biological reactions occur
61
Describe batch culture
* Fixed amount of nutrients added at the start * Microorganisms go through lag, log, stationary and sometimes decline * Product formed for a short time and then process starts again
62
Give an example of batch culture
Making antibiotics
63
Describe continuous flow
* Nutrients added all the time * Microorganisms maintained at the log phase * Product formed all the time for a long period
64
Give an example of continuous flow
Single cell protein
65
What are the two main methods of production?
Batch culture and continuous flow
66
Define facultative in terms of anaerobic respiration
Can respire with/without oxygen
67
Define obligate in terms of anaerobic respiration
Can only respire without oxygen
Biology
flashcards
Decks in class (29)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions