Practice Questions (Multiple Choice) Flashcards

1
Q

Please choose the correct answer regarding viruses:
A.Viruses belong to the microbial kingdom; however, they form separate domain of life that is distinct from Bacteria, Archaea and Eukaryotes.
B. Viruses belong to the infectious agents that have no kingdom membership; however, viruses contain genetic information (DNA or RNA) surrounded by a protein coat termed a capsid.
C. One of viral characteristics is that its microcellular structure established a parasitic mode of life.
D. Correct are A and C
E. Correct are B and C

A

B

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2
Q

Q2. Which hypothesis suggests that viruses evolved from replicative elements preceding early life forms?
A. The ‘virus early’ hypothesis
B. The ‘regression’ hypothesis
C. The ‘escaped genes’ hypothesis
D. The ‘viral ancestor’ hypothesis

A

A

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3
Q

Q3. Why do viruses have no kingdom membership?
A. They are too small to be classified.
B. They lack genetic material.
C. They do not belong to any cellular organism.
D. They have characteristics of both plants and animals.

A

C

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4
Q

Q4. Chose correct answer regarding viral envelopes:
A. Viral envelope is rigid membranous layer that is coded by viral genome.
B. Viral envelopes are flexible membranous structures that originate from the host cell in animal viruses.
C. Viral envelopes are used as viral ID; they can have enzymatic activities and play the role in viral nucleic acid replication.
D. Correct are B and C
E. All the above

A

D

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5
Q

Q5. How do viruses reproduce?
A. Through binary fission
B. By meiosis
C. By invading a host cell and taking over its machinery.
D. Through mitosis

A

C

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6
Q

What is NOT correct about viral genome and replication?

A.Viruses have variety of shapes and symmetries (Helical, Icosahedral. Complex symmetry); however, they can ONLY have DNA as genetic information storage.
B. Nucleic acid inside of viral capsid can be DNA (single stranded or double stranded) or RNA (single stranded or double stranded); however, most viruses contain RNA as genetic information storage.
C. In DNA viruses, the nucleic acid is linear, with some exceptions of circular double stranded DNA
D. Incorrect are B and C
E. All the above is incorrect.

A

A

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7
Q

Q7. Chose the correct answer regarding viral replication:
A.The viral nucleic acid and proteins copies are manufactured by the cell’s machinery; A virus cannot reproduce by itself, it must invade a host cell and take over the cell activities, eventually causing destruction of the cell and killing it.
B. During lytic infection, the viral DNA gets integrated with the host cell DNA where it gets copied with the host cell DNA.
C. During lysogenic infection, a virus enters the host cell, makes a copy of itself, and causes the cell to burst, or lyse.
D. Viruses cannot survive out of host cell at all. As soon as a virus gets in contact with water and hard surface, it will burst and die.
E. A cold virus cannot survive on indoor surfaces while flu viruses can survive in the air for several hours, especially at lower temperatures; enteric viruses, viruses that affect our gut microbiome can survive for weeks on a surface if conditions are suitable.

A

A

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8
Q

How do enveloped viruses obtain their envelope?
A. They produce it using their own machinery.
B. It is inherited from the host cell.
C. It forms during viral replication.
D. They steal it from other viruses.

A

B

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9
Q

Which method is NOT used for penetration or viral entry?
A. Fusion of the viral envelope with host membrane
B. Endocytosis in vesicle
C. Injection of nucleic acid
D. Encapsulation in a protein coat

A

D

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10
Q

Which organelles in eukaryotic cells are thought to be derived from bacteria and have their own DNA?
A. Nucleus and Golgi apparatus
B. Mitochondria and chloroplasts
C. Endoplasmic reticulum and lysosomes
D. Ribosomes and peroxisomes

A

B

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11
Q

Which group of protists is correctly matched with its characteristics?
a. Euglenozoans - contain hydrogenosomes.
b. Alveolates - form red tides in unpolluted coastal zones
c. Stramenopiles - exclusively marine and form shell-like structures
d. Diplomonads - have a single large mitochondrion and feed on bacteria via phagocytosis

A

b

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12
Q

What is the primary role of diatoms among the stramenopiles?
A. Cause malaria in humans
B. Form red tides in polluted coastal zones
C. Major components of planktonic microbial communities
D. Form shell-like structures exclusively in marine environments

A

C

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13
Q

. Chose the correct answer regarding primary and secondary endosymbiotic theory:
A. Primary endosymbiosis gave rise to the chloroplast in the common ancestor of green algae, red algae, and plants.
B. Cells of green and red algae were engulfed, and their chloroplasts were stably retained (new cells become phototrophic).
C. New phototrophic cells of euglenids and chlorarachniophytes is the result of secondary endosymbiosis in green algae.
D. Correct are A and B
E. All the above is correct (A, B, and C).

A

E

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14
Q

Chose correct answer regarding Euglenozoans:
A. Euglenozoans are divided into two groups, kinetoplastids and euglenids; euglenids are characterized by large mass of DNA in single large mitochondrion.
B. Euglenozoans are divided into two groups, kinetoplastids and euglenids; euglenids are characterized by two flagella, chloroplasts, and phagocytosis of bacterial cells.
C. Euglenozoans are divided into two groups, kinetoplastids and euglenids; kinetoplastids are characterized by large mass of DNA in single large mitochondrion.
D. Correct are B and C
E. None of the above

A

D

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15
Q

According to the RNA world theory, which molecule catalyzed the formation of first simple peptides?

a) Proteins
b) RNA
c) Lipids
d) DNA
e) Both, RNA and DNA

A

b

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16
Q

What is the significant event that marked the end of the Archaean era?

a) Development of methanogenesis
b) Emergence of cyanobacteria
c) Formation of metal precipitates
d) Oxygenation event

A

d

17
Q

What is the key characteristic that distinguishes lipids in bacteria from lipids in archaea?

a) Ester bond in bacteria and ether bond in archaea
b) Ether bond in bacteria and ester bond in archaea
c) Double bond in bacteria and single bond in archaea
d) Single bond in bacteria and double bond in archaea
e) Isoprenoid bond in archaea and ester/ether bonds in bacteria

A

a

18
Q

Which theory proposes that the first eukaryotic cell initially had a nucleus?

a) Hypothesis 1
b) Hypothesis 2
c) Surface origin theory
d) Subsurface origin theory
e) RNA world

A

a

19
Q

What type of recombination involves short segments of highly similar DNA sequences?

a) HGT recombination
b) Nonhomologous recombination
c) Homologous recombination
d) Homologous sequences
e) Similar sequences

A

c

20
Q

What is the main reason for using rRNA genes to determine phylogeny?

a) Universally distributed
b) Highly mutable
c) Unique to each organism
d) Rapidly changing
e) Present in all 3 lineages

A

a

21
Q

In lecture we described the three theories on the emergence of the first cell. Which theory involves interactions between alkaline hot water and cold acidic ocean water?

a) Surface origin theory
b) Subsurface origin theory
c) RNA world theory
d) O2 evolution theory
e) Chemical bonds and interactions

A

b

22
Q

Which group of organisms can perform photosynthesis and convert light energy into chemical energy in the form of ATP and NADH?

a) Heterotrophs
b) Chemolithotrophs
c) Phototrophs
d) Autotrophs
e) Chemoorganotrophs

A

c

23
Q

In which type of photosynthesis is H2O oxidized to produce O2 as a byproduct?

a) Anoxygenic photosynthesis
b) Oxygenic photosynthesis
c) Hydrogen sulfide photosynthesis
d) Reverse Electron Flow
e) Hydroxypropionate cycle

A

b

24
Q

Which group of organisms is known for anoxygenic photosynthesis and produces S0 as a byproduct stored outside of cell?

a) Purple Sulfur Bacteria
b) Cyanobacteria
c) Green Sulfur Bacteria
d) Purple Non-Sulfur Bacteria
e) Both a and c

A

c

25
Q

Chemolithotrophs can use which of the following as potential energy sources (electron donor, NOT acceptor)?

a. H2
b. O2
c. CO2
d. NO3-/NO2-
e. All of the above

A

a

26
Q

Which two organisms are known as metal reducers (respire metals) through nanowires?

a. Nitrifiers and denitrifiers
b. M. oxyfera and Beggiatoa
c. Shewanella and Geobacter
c. Aquifex and Rhodococcus

A

c

27
Q

Which organism is known as proton respiring organism (H+ respiration)?

a. H+ respiration is common in all Archaea.
b. Pyrococcus furiosus
c. Desulfovibrio sp.
d. None of the above
e. Both b and c

A

b

28
Q

What is the name of the organism that evolved as oxygenic phototroph but performs anoxygenic photosynthesis if PSII is blocked?

a. Methylomirabilis oxyfera
b. Oscillatoria limnetica
c. Brocadia anammoxidans
d. Nitrosomonas europea
e. None of the above (oxygenic phototrophs cannot perform anoxygenic photosynthesis)

A

b

29
Q

Anammox (Anaerobic Ammonia Oxidation) is a process that occurs in (chose ONE correct)

a. Phototrophic organisms
b. Anoxic conditions
c. Aerobic conditions
d. Hydrothermal vents
e. Between ANME and SRB

A

b

30
Q

Which of the following is NOT an alternative electron acceptor in anaerobic respiration? (chose ONE correct)

a.Nitrate (NO3-)
b. Oxygen (O2)
c. Sulfate (SO42-)
d. Carbon dioxide (CO2)
e. Nitrite (NO2-)

A

b

31
Q

Methanotrophs are a subgroup of methylotrophs that utilize certain compounds as energy source (electron donor) (chose ONE correct)

a. Methane (CH4)
b. Formaldehyde (CH2O)
c. Ethanol (C2H5OH)
d. Nitrite (NO2-) or methane (CH4)
e. Methane (CH4) or sulfate (SO42-)

A

a

32
Q

Which metabolic pathway is the most efficient in terms of energy for CO2 fixation? Which one is the most abundant? (chose ONE correct)

a. Calvin Cycle is the most energetically efficient, but Reverse TCA cycle is the most energetically efficient
b. Reverse TCA cycle is the most abundant, but Wood-Ljungdahl pathway is the most energetically efficient.
c. Wood-Ljungdahl pathway is the most energetically efficient, but hydroxypropionate is the most abundant
d. Wood-Ljungdahl pathway is the most efficient energetically, but Calvin cycle is the most abundant.
e. Calvin cycle is the most abundant and the most energetically efficient

A

d

33
Q

In anaerobic methane oxidation, which two types of organisms work together? (chose ONE correct)

a. Methanogens and Anaerobic Ammonium-Oxidizing Bacteria (ANAMMOX)
b. Methanogens and Nitrate-Respiring Bacteria
c. Sulfate-Reducing Bacteria (SRB) and Methanogens
d. Methanotrophs and Sulfur-Oxidizing Bacteria
e. Aerobic methanotrophs and Sulfate-Reducing Bacteria (SRB)

A

c

34
Q

Chose correct answer

a. Purple and green sulfur bacteria succeeded (came after) cyanobacteria on Earth (0.5 billion years after them)
b. Anoxygenic photosynthesis was the first form of photosynthesis on Earth
c. The key evolutionary inventions of cyanobacteria were to connect the two forms of reaction centers (as PSI and PSII) and evolve the ability to use H2S as a photosynthetic electron donor (Oscillatoria limnetica).
d. Purple Sulfur Bacteria and Cyanobacterial PSI are the same type (quinone based)
e. Green Sulfur Bacteria and Cyanobacterial PSII are the same type (ferredoxin based)

A

b

35
Q

Chose correct answer (s)

a. Purple sulfur bacteria are anoxygenic phototrophs known by the ability to use H2O to drive photosynthesis; two representative genera are Chromatiaceae and Ectothiorhodospiraceae.
b. Purple, non-sulfur bacteria are known by the ability to use organic compounds as energy source, perform fermentation and anaerobic respiration; key representative genus is Rhodobacter.
c. Thermomicrobium is the example of green, non-sulfur bacteria that contains 1,2 dialcohols instead of glycerol (neither ether no ester bond).
d. Purple, non-sulfur bacteria are known by the ability to use lactate as energy source; two representative genera are Chromatiaceae and Ectothiorhodospiraceae.
e. Both, b and c are correct

A

e

36
Q
A