Introduction to Microbiology
Questions and Answers in Microbiology
1. The first observer of bacteria under the microscope was:
A) Robert Hoock
B) Robert Koch
C) Anton van Leeuwenhoek
D) Beijerinck
2. The scientist Sergei Winogradsky is connected with the development of:
A) Microbial ecology
B) Heterotrophic metabolism
C) Aerobic bacteria
D) All of the above
3. Which scientist(s) related to the field of microbiology influenced the area of agronomy?
I) Fleming II) Beijerinck III) Winogradsky
A) Only II)
B) Only III)
C) II) and III)
D) I), II) and III)
4. If a grape plantation has an unknown illness, and you must discover the cause, what would you do or what would you ask a specialized laboratory?
A) Eliminate planting
B) Take a seed plant, inoculate a sick and a healthy plant, and then isolate both plants
C) Apply pesticides without knowing the causal agent
D) Take a sample, isolate the potential pathogen, and inoculate it into healthy plants
5. The elimination of resistant forms was achieved through the experiment by:
A) Tyndall with successive heating
B) Koch’s postulates
C) Pasteur’s pasteurization
D) Pasteur with swan neck flask
6. The most important discovery for the development of microbiology was:
A) Koch’s postulates
B) The development of vaccines
C) The development of the microscope
D) All of the above
7. The small size of bacteria results in:
A) Low rate of waste output
B) Low surface area to volume ratio
C) High growth rates
D) Reduced adaptation to nutritional changes
8. In relation to the bacterial wall, it is correct to say:
A) All bacteria have a wall
B) Antibiotics such as penicillin and its derivatives are not active in archaea
C) The composition of the peptidoglycan wall of prokaryotes is complex
D) Gram-negative bacteria have no peptidoglycan
9. In relation to lipopolysaccharide, it is correct that:
A) It occurs in bacteria such as E. coli and Salmonella
B) It is found in archaea
C) It is impermeable
D) All are correct
10. Regarding resistance structures of prokaryotes, it is correct that:
A) They resist radiation due to the presence of calcium and dipicolinic acid
B) They have SASP proteins to protect DNA
C) They have an outer layer (exosporium) of peptidoglycan
D) They are metabolically active structures
11. Porins relate to:
A) Protein channels present in membranes of Gram-negative and Gram-positive bacteria
B) Chemoreceptors located in the periplasm
C) Proteins that increase the permeability of LPS to large molecules
D) Hydrophilic pores located in the LPS of Gram-negative bacteria
12. Regarding bacterial flagella, we can say that:
I) They are formed of flagellin and move by rotation
II) They allow movement in a straight line when rotating clockwise
III) In Gram-positive bacteria, they anchor to the cell through two proteins, MS and P
IV) Peritrichous flagellation corresponds to a tuft of flagella at both cell poles
V) In a chemical gradient, they change direction of rotation, and the result is random movements
A) I and III
B) I, II and III
C) III and V
D) II, III and IV
13. The bacterial structure known as a flagellum corresponds to:
A) Spores
B) Fimbriae
C) Flagellum
D) Pili
14. In relation to plasmids, it is correct that:
A) They are the genetic material of the nuclear region
B) They are extrachromosomal genetic material
C) They are a protein source present in some prokaryotes
D) They confer selective disadvantages, such as antibiotic resistance
15. Chemotaxis corresponds to:
A) Chemical response to stimuli
B) Flagellar movement in a straight line
C) Bacterial random movements
D) Movement in response to a chemical stimulus
16. Cell membranes with isoprenoids linked by ether linkages to glycerol are characteristic of:
I) Viruses II) Bacteria III) Archaea IV) Protozoa
A) I and II
B) I only
C) III only
D) I and IV
17. Mycoplasma is a bacterium that is characterized by:
A) Lack of peptidoglycan
B) Presence of phospholipid bilayers with cholesterol
C) Being resistant to penicillin
D) All of the above
18. Encapsulated bacteria capable of forming spores have advantages over others because:
A) Spore formation is an important virulence factor
B) They can multiply in tissues by avoiding phagocytic attack
C) They can withstand adverse conditions such as lack of nutrients due to the protection of the capsule
D) They can be detected quickly by laboratory techniques
19. A Gram-negative bacterium is characterized by:
A) Having a membrane with antigenic properties
B) Possessing peptidoglycan
C) Being encapsulated
D) Being flagellated
20. A cyanobacterium is structurally characterized by:
A) Being a eukaryotic autotroph
B) Having gas vacuoles
C) Being a heterotroph
D) Being aquatic
21. A plasmid is characterized by:
A) Carrying genes essential for bacterial growth
B) Carrying a small number of genes that confer selective advantages to bacteria
C) Being extrachromosomal genetic material with replication dependent on the chromosome
D) None of the above
22. The bacterial chromosome is:
A) Covalently closed, single-stranded DNA
B) Extrachromosomal DNA
C) A DNA molecule not associated with histones
D) Haploid DNA
23. A prokaryote such as Bacillus is characterized by:
A) Living in extreme environments
B) Lacking LPS
C) Lacking peptidoglycan
D) Being anaerobic
24. The fundamental difference between a Gram-positive and a Gram-negative bacterium is:
A) The presence of peptidoglycan
B) The composition of the membrane system
C) The presence of a cell membrane
D) The ability to form spores
25. Fungi belong to:
A) The prokaryotic domain Eukarya
B) The eukaryotic domain Eukarya
C) The eukaryotic domain Fungi
D) The prokaryotic domain Bacteria
26. In relation to viruses, it is correct that:
I. They are host-specific
II. They have an inactive extracellular metabolic state
III. They have a capsule of similar composition to the cell membrane
IV. All animal viruses are composed of DNA and proteins
A) I, II and IV
B) II, III and IV
C) I and IV
D) I and III
27. A prophage has the ability to:
A) Infect bacteria
B) Synthesize components of the capsid
C) Cause cell lysis
D) Be transferred from one bacterium to the next generation through bacterial division
28. A sex pilus serves for:
A) Specific binding of bacteriophages
B) Vertical transfer of genetic information
C) Motility
D) A and B
29. Regarding endotoxin, it is correct that:
A) It is present in Gram-negative and Gram-positive bacteria
B) It is associated with peptidoglycan
C) It is a virulence factor of some bacteria
D) It has antiphagocytic activity
30. Mycobacterium tuberculosis, a bacterium discovered by Koch, is structurally characterized by:
A) Lack of LPS
B) Having a Gram-positive type wall
C) Presence of waxes and glycolipids in its wall
D) All are correct
31. A characteristic of the cell membrane of bacteria is:
A) The presence of peptidoglycan
B) Providing transport proteins
C) The presence of cytochromes on the inside for cellular respiration
D) Being a semipermeable barrier
32. The flagellum gives the bacterium that possesses it:
A) Antiphagocytic capacity
B) An energy disadvantage
C) Responsiveness to an oxygen gradient
D) A and C are correct
33. Which structural components of bacteria allow them to adhere to substrates?
I) LPS II) Inclusions III) Capsules IV) Gas vacuoles
A) I, II and III
B) II and III
C) II, III and IV
D) I and III
34. If an organism grows in a medium with limited nitrogen, the microorganism will produce:
A) Capsules
B) Magnetosomes
C) Inclusions
D) Spores
35. The following are structures of a cyanobacterium:
A) Peptidoglycan
B) Gas vacuoles
C) LPS
D) All of the above
36. An evolutionary link between the eukaryotic and prokaryotic cell is:
A) A common ancestor, which would be the archaea
B) The characteristics of mitochondrial ribosomes
C) The structural similarity of the cell membrane
D) Aerobic metabolism in some prokaryotes
37. Staphylococcus aureus is characterized by:
I) Grouping in clusters
II) Presence of capsules
III) Presence of spores
IV) Being Gram-positive
A) I, II and III
B) I and III
C) III and IV
D) I and IV
38. A Bacillus bacterium will produce ______ if it uses up the nutrients in the medium:
A) Inclusions of glycogen as a carbon source
B) Spores to survive without nutrition
C) Capsules to prevent drying
D) None of the above
39. A correct definition of a prokaryote is:
A) A bacterium without organelles or a nuclear membrane
B) A bacterium or archaeon without a defined nucleus
C) A cell without a nucleus and a cell wall
D) A cell without membrane-bound organelles or a nuclear membrane