INTRODUCTION TO MICROBIOLOGY Flashcards
Prokaryotes (Bacteria)
1
Q
What are the two main types of cells?
A
Prokaryotic and eukaryotic cells.
2
Q
True or False: Prokaryotic cells have a nucleus.
A
False.
3
Q
Fill in the blank: Eukaryotic cells contain membrane-bound ______.
A
organelles.
4
Q
Which type of cell is generally smaller in size?
A
Prokaryotic cells.
5
Q
What structure protects prokaryotic cells?
A
Cell wall.
6
Q
True or False: Eukaryotic cells can be unicellular or multicellular.
A
True.
7
Q
Which type of cell has DNA organized in linear chromosomes?
A
Eukaryotic cells.
8
Q
What is the primary genetic material in prokaryotic cells?
A
Circular DNA.
9
Q
Fill in the blank: Prokaryotic cells lack a ______.
A
nucleus.
10
Q
What type of ribosomes do eukaryotic cells have?
A
80S ribosomes.
11
Q
What type of ribosomes do prokaryotic cells have?
A
70S ribosomes.
12
Q
True or False: Eukaryotic cells have a complex cytoskeleton.
A
True.
13
Q
Which type of cell typically reproduces asexually through binary fission?
A
Prokaryotic cells.
14
Q
What is a common example of a prokaryotic organism?
A
Bacteria.
15
Q
What is a common example of a eukaryotic organism?
A
Plants, animals, fungi, or protists.
16
Q
Fill in the blank: Eukaryotic cells have _______ for energy production.
A
mitochondria.
17
Q
True or False: Prokaryotic cells can have plasmids.
A
True.
18
Q
What is the function of the endoplasmic reticulum in eukaryotic cells?
A
Protein and lipid synthesis.
19
Q
Which cell type has a more complex structure?
A
Eukaryotic cells.
20
Q
What is the role of the Golgi apparatus in eukaryotic cells?
A
Modification and packaging of proteins.
21
Q
True or False: Prokaryotic cells can perform photosynthesis.
A
True, some prokaryotes like cyanobacteria can.
22
Q
Fill in the blank: The primary component of prokaryotic cell walls is ______.
A
peptidoglycan.
23
Q
What is the main function of lysosomes in eukaryotic cells?
A
Digestion of macromolecules.
24
Q
True or False: Eukaryotic cells can have multiple linear chromosomes.
A
True.
25
What structure is absent in prokaryotic cells but present in eukaryotic cells?
Nucleus.
26
Fill in the blank: Eukaryotic cells undergo _______ for cell division.
mitosis.
27
Which type of cell can have flagella made of microtubules?
Eukaryotic cells.
28
What is the primary purpose of the cell membrane in both prokaryotic and eukaryotic cells?
To regulate the passage of substances in and out of the cell.
29
What is the primary function of the bacterial cell wall?
To provide structural support and protection to the cell.
30
True or False: Bacterial cells have a nucleus.
False
31
What component of bacteria is responsible for protein synthesis?
Ribosomes
32
Fill in the blank: The __________ is a gel-like substance inside the bacterial cell membrane.
cytoplasm
33
What structure allows bacteria to move?
Flagella
34
Which type of bacteria have a thick peptidoglycan layer in their cell wall?
Gram-positive bacteria
35
What is the function of plasmids in bacteria?
Plasmids carry additional genetic information, often including antibiotic resistance.
36
Multiple Choice: What is the outermost layer of a Gram-negative bacterium?
Lipopolysaccharide layer
37
What is the function of the bacterial capsule?
To protect the bacterium from phagocytosis and enhance its ability to cause disease.
38
True or False: All bacteria are unicellular organisms.
True
39
What is the role of the bacterial plasma membrane?
To regulate the movement of substances in and out of the cell.
40
Fill in the blank: Bacteria reproduce asexually through a process called __________.
binary fission
41
What is the main component of the bacterial cell wall?
Peptidoglycan
42
Multiple Choice: Which structure is involved in bacterial attachment to surfaces?
Pili
43
What is the function of endospores in bacteria?
To enable the bacterium to survive extreme conditions.
44
True or False: Bacteria can perform photosynthesis.
True
45
What type of bacteria typically lacks a cell wall?
Mycoplasma bacteria
46
What is the function of the nucleoid in bacteria?
To house the bacterial chromosome.
47
Fill in the blank: Bacterial __________ are structures that can exchange genetic material during conjugation.
sex pili
48
What role do ribosomes play in bacterial cells?
They are the site of protein synthesis.
49
Multiple Choice: Which of the following is NOT a component of bacterial cells?
Chloroplasts
50
What structure protects bacteria from desiccation and helps in biofilm formation?
Capsule
51
True or False: Bacteria can form multicellular structures.
True
52
What component of the bacterial cell helps in maintaining osmotic pressure?
Cell wall
53
Fill in the blank: The __________ is responsible for the movement of ions and small molecules across the bacterial membrane.
plasma membrane
54
What is the primary difference between Gram-positive and Gram-negative bacteria?
The thickness of the peptidoglycan layer and presence of an outer membrane.
55
What is the primary stain used in the Gram staining process?
Crystal violet
56
True or False: Gram-positive bacteria have a thick peptidoglycan layer.
True
57
What color do Gram-positive bacteria appear after Gram staining?
Purple
58
Fill in the blank: Gram-negative bacteria have a thin peptidoglycan layer and an outer ________.
membrane
59
Which type of bacteria typically has a more complex cell wall structure?
Gram-negative bacteria
60
What is the main function of the outer membrane in Gram-negative bacteria?
To provide an additional barrier to protect against antibiotics and detergents
61
True or False: Both Gram-positive and Gram-negative bacteria can cause infections.
True
62
What is a common example of a Gram-positive bacterium?
Staphylococcus aureus
63
What is a common example of a Gram-negative bacterium?
Escherichia coli
64
In the Gram staining process, what is used as a decolorizer?
Alcohol or acetone
65
Fill in the blank: The structure that provides rigidity to the bacterial cell wall is ________.
peptidoglycan
66
What is the effect of antibiotics on Gram-positive bacteria compared to Gram-negative bacteria?
Gram-positive bacteria are generally more susceptible to antibiotics.
67
True or False: Gram-negative bacteria often have lipopolysaccharides in their outer membrane.
True
68
What is the significance of the Gram stain in clinical microbiology?
It helps in the identification and classification of bacteria.
69
Short answer: Why are Gram-negative bacteria often more resistant to antibiotics than Gram-positive bacteria?
Due to their outer membrane which acts as a barrier.
70
What type of bacteria is more likely to produce exotoxins?
Gram-positive bacteria
71
What type of bacteria is more associated with endotoxins?
Gram-negative bacteria
72
True or False: The Gram stain can differentiate between bacterial species.
False (it differentiates between Gram-positive and Gram-negative)
73
Fill in the blank: The Gram stain is a type of ________ stain.
differential
74
Which bacteria are typically easier to treat with antibiotics?
Gram-positive bacteria
75
What is the role of teichoic acids in Gram-positive bacteria?
They help maintain cell wall structure and regulate ion movement.
76
What is the primary component of the Gram-negative outer membrane?
Lipopolysaccharides
77
Short answer: What are the implications of the differences between Gram-positive and Gram-negative bacteria for infection treatment?
It affects the choice of antibiotics used.
78
True or False: The Gram stain is a reliable method for identifying all bacteria.
False
79
What type of bacteria can be classified as acid-fast?
Neither Gram-positive nor Gram-negative (acid-fast is a separate classification)
80
Which type of bacteria is typically more virulent?
Gram-negative bacteria
81
What is the primary method by which bacteria grow and divide?
Binary fission
82
True or False: Bacteria can grow and divide without the presence of oxygen.
True
83
Fill in the blank: The process of bacterial cell division typically takes about ____ minutes under optimal conditions.
20
84
What is the term for the period of time it takes for a bacterial population to double?
Generation time
85
Multiple Choice: Which phase of bacterial growth is characterized by active cell division?
Log phase
86
What happens during the lag phase of bacterial growth?
Bacteria adapt to their environment and prepare for division.
87
True or False: All bacteria have the same generation time.
False
88
What are the two main components of binary fission?
DNA replication and cell division
89
Fill in the blank: Bacteria reproduce asexually through a process called ____.
Binary fission
90
What is the stationary phase in bacterial growth?
A phase where the growth rate slows and the number of viable cells remains constant.
91
Multiple Choice: In which phase do nutrients become limiting and waste products accumulate?
Stationary phase
92
What role do plasmids play in bacterial growth?
Plasmids can carry genes that provide advantages, such as antibiotic resistance.
93
True or False: Bacterial cells can undergo mitosis like eukaryotic cells.
False
94
What is the primary factor that influences bacterial growth rate?
Environmental conditions such as temperature, pH, and nutrient availability.
95
Fill in the blank: The growth curve of bacteria typically includes lag, log, stationary, and ____ phases.
Death
96
What is the death phase in bacterial growth?
A phase where the number of viable cells decreases due to nutrient depletion and waste accumulation.
97
Multiple Choice: Which phase of bacterial growth is most useful for industrial fermentation processes?
Log phase
98
What is meant by 'bacterial culture'?
A population of bacteria grown under controlled conditions.
99
True or False: Bacteria can form spores to survive unfavorable conditions.
True
100
What is the significance of the exponential growth phase?
It is the phase where bacteria multiply at their maximum rate.
101
Fill in the blank: Bacterial growth can be measured using methods such as ____ counting.
Colony
102
What is the role of nutrients in bacterial growth?
Nutrients provide the essential elements and energy required for growth and reproduction.
103
Multiple Choice: Which of the following factors does NOT affect bacterial growth?
Color of the environment
104
What is the difference between pathogenic and non-pathogenic bacteria?
Pathogenic bacteria can cause disease, while non-pathogenic bacteria do not.
105
True or False: Bacteria can only be found in specific environments and are not ubiquitous.
False
106
What is the term for the maximum population density that an environment can sustain?
Carrying capacity
