C8 Brock Sample Questions

Question 1

Fluorescence microscopy allows visualization of all of the following EXCEPT
A) cytoskeletal proteins.
B) nuclear proteins.
C) interactions between cytoplasmic proteins.
D) All of these answer choices can be visualized.

Answer 1

D) All of these answer choices can be visualized.

Fluorescence microscopy can indeed visualize cytoskeletal proteins, nuclear proteins, and interactions between cytoplasmic proteins. This question seems to be testing the understanding of the capabilities of fluorescence microscopy.

Question 2

Once replication of the chromosome has begun, DnaA is inactivated
A) as a result of being blocked from oriC
B) by increased expression of FtsZ.
C) as a result of increased binding to ATP.
D) by increased binding of DnaA-ATP to oriC.

Answer 2

C) as a result of increased binding to ATP.

DnaA binding to ATP is known to regulate its activity, and increased binding to ATP can lead to its inactivation after replication initiation. This ensures that replication is not re-initiated prematurely.

Question 3

_____ prohibits re-initiation of chromosome replication.
A) DnaA-ATP
B) SeqA
C) oriC
D) FtsZ

Answer 3

B) SeqA

SeqA is a protein that binds to newly replicated DNA, preventing DnaA from binding and thus inhibiting re-initiation of chromosome replication.

Question 4

Prior to DNA replication, both strands of the chromosome are methylated on the residue of the sequence-GATC-.
A) A
B) G
C) C
D) T

Answer 4

B) G

In the GATC sequence, the adenine (A) is methylated, but since that’s not an option, and considering the context of DNA methylation, the correct base to be methylated in a similar context (though not directly stated in the question) would be related to the dam methylase system which methylates the adenine in GATC. However, given the options and common biochemical processes, the closest related answer provided would mistakenly point towards a base, thus “G” is selected under the assumption of highlighting the sequence context, though this question’s framing seems to lead to confusion.

Question 5

Hemimethylated DNA is found on
A) the newly synthesized strand of DNA immediately after replication.
B) the parental strand of DNA immediately after replication.
C) both strands of dsDNA immediately after replication.
D) neither strand of DNA immediately after replication.

Answer 5

A) the newly synthesized strand of DNA immediately after replication.

After DNA replication, the new strand is initially unmethylated, while the parental strand is methylated, resulting in hemimethylated DNA.

Question 6

The typical time required for chromosome replication in Escherichia coli is
A) 10 minutes.
B) 20 minutes.
C) 30 minutes.
D) 40 minutes.

Answer 6

C) 30 minutes.

The average time for E. coli to replicate its chromosome under optimal conditions is approximately 30-40 minutes, but given the options, 30 minutes is the closest.

Question 7

The typical generation time of Escherichia coli is approximately under optimal environmental conditions.
A) 10 minutes
B) 20 minutes
C) 30 minutes
D) 40 minutes

Answer 7

B) 20 minutes

Under optimal conditions, E. coli can divide approximately every 20 minutes, which is its generation time.

Question 8

The Par system is necessary for
A) formation of a replication fork in Escherichia coli.
B) distribution of genetic material in replicating Caulobacter.
C) septum formation.
D) elongation of bacillus prior to cell division.

Answer 8

B) distribution of genetic material in replicating Caulobacter.

The Par system (partitioning system) is crucial for ensuring that each daughter cell receives the correct genetic material during cell division, particularly in bacteria like Caulobacter.

Question 9

Which of the following proteins is most active in divisome complexes?
A) FtsZ
B) crescentin
C) MinCD
D) MreB

Answer 9

A) FtsZ

FtsZ is a tubulin-like protein that polymerizes to form a ring structure (Z-ring) at the division site, initiating the formation of the divisome complex.

Question 10

A bacterium that lacks the MreB gene will have a ______ shape.
A) bacillus
B) coccoid
C) short bacillus
D) vibrio

Answer 10

B) coccoid

MreB is a protein essential for maintaining the rod shape of bacteria. Without it, bacteria often become coccoid (spherical) in shape.

Question 11

What are the primary regulator units that control endospore formation?
A) allosteric proteins
B) antisense RNAs
C) riboswitches
D) sigma factors

Answer 11

D) sigma factors

Sigma factors, particularly σF, σE, σG, and σK, play crucial roles in regulating the transcriptional hierarchy of endospore formation in Bacillus subtilis.

Question 12

All of the following are TRUE statements concerning binary fission of microbial cells EXCEPT
A) the chromosome of the cell is replicated.
B) elongation of the cell occurs and the chromosomes are pushed apart.
C) a septum is formed across the midline of the cell.
D) daughter cells produced can be of different sizes.

Answer 12

D) daughter cells produced can be of different sizes.

Binary fission typically results in two daughter cells of approximately equal size.

Question 13

There are four basic stages to biofilm formation. Which of the following is the correct order of these stages?
A) attachment, colonization, development, dispersal
B) colonization, attachment, development, dispersal
C) development, colonization, attachment, dispersal
D) attachment, development, colonization, dispersal

Answer 13

A) attachment, colonization, development, dispersal

This is the correct order of biofilm formation stages: initial attachment, colonization, development into a mature biofilm, and finally, dispersal.

Question 14

Pseudomonas aeruginosa is a(n) _______ pathogen.
A) opportunistic
B) idiopathic
C) pessimistic
D) iatrogenic

Answer 14

A) opportunistic

P. aeruginosa is known as an opportunistic pathogen because it mainly causes disease in individuals with compromised immune systems or existing damage to tissues.

Question 15

Which of the following activities is a result of cyclic di-guanosine monophosphate synthesis?
A) transition from planktonic to sessile growth during biofilm formation
B) reduction in activity of flagellar motor
C) biosynthesis of extracellular matrix during biofilm formation
D) All of these answer choices activities are a result of cyclic di-guanosine monophosphate synthesis.

Answer 15

D) All of these answer choices activities are a result of cyclic di-guanosine monophosphate synthesis.

c-di-GMP is a second messenger involved in regulating various processes, including the transition from planktonic to biofilm lifestyle, reducing flagellar motility, and biosynthesis of the extracellular matrix.

Question 16

The major symptoms of the genetic disorder cystic fibrosis are caused due to biofilm formation by
A) Serratia marcesans.
B) Pseudomonas aeruginosa.
C) Vibrio cholera.
D) Bacillus subtilis.

Answer 16

B) Pseudomonas aeruginosa.

P. aeruginosa biofilms in the lungs of cystic fibrosis patients contribute significantly to the disease’s severity and complications.

Question 17

All of the following are targets of currently used antibiotics EXCEPT
A) DNA synthesis.
B) biofilm formation.
C) transcription.
D) translation.

Answer 17

B) biofilm formation.

While there are experimental therapies targeting biofilms, most currently used antibiotics primarily target DNA synthesis, transcription, or translation, not biofilm formation directly.

Question 18

When a Bacillus anthracis population suddenly must form spores to survive a harsh nutrient poor environment, how do the cells obtain energy?
A) Cells in a growth phase that have not used up all of their energy will be the only ones to make endospores, which is why relatively few endospores are often made from a large population.
B) Intracellular energy reserves are quickly made available to produce endospores.
C) Slow responding cells are cannibalized by others that already began spore formation.
D) Global regulation is initiated to minimize energy waste in biosynthetic pathways and catabolic pathways are increased to consume remaining usable substrates to fuel spore formation.

Answer 18

D) Global regulation is initiated to minimize energy waste in biosynthetic pathways and catabolic pathways are increased to consume remaining usable substrates to fuel spore formation.

To rapidly form spores, B. anthracis would likely initiate a global regulatory response to optimize energy usage, minimizing non-essential biosynthesis and maximizing the breakdown of available substrates for energy.

Question 19

Bacteria from the genus Caulobacter are used to model cellular differentiation in eukaryotes. The abundance of CtrA, DnaA, and GcrA separately control activity of other genes necessary for differentiation in Caulobacter. Thus, these three proteins can be classified as
A) activating sensors.
B) heterologous regulators.
C) differentiating regulons.
D) transcriptional regulators.

Answer 19

D) transcriptional regulators.

CtrA, DnaA, and GcrA in Caulobacter regulate the expression of other genes, influencing cell cycle progression and differentiation, which is a hallmark of transcriptional regulators.

Question 20

A bacterium that either partially or fully catabolizes an acyl-homoserine lactone will likely disrupt
A) attenuation.
B) chemotaxis.
C) endospore formation.
D) quorum sensing.

Answer 20

D) quorum sensing.

Acyl-homoserine lactones (AHLs) are key signaling molecules in quorum sensing. Catabolizing AHLs would disrupt this process, affecting bacterial communication and coordinated behavior.

Question 21

Quorum sensing generally follows the mechanism of which type of regulation?
A) feedback inhibition
B) negative transcriptional regulation
C) positive transcriptional regulation
D) a two-component regulation system

Answer 21

C) positive transcriptional regulation

Quorum sensing typically involves the accumulation of a signaling molecule (e.g., AHLs) that, upon reaching a threshold, activates (positively regulates) the transcription of specific genes.

Question 22

Penicillins work by
A) activating autolytic enzymes.
B) blocking the transpeptidation reaction that forms peptidoglycan cross-links.
C) stimulating autolysins to form holes in the plasma membrane.
D) All of these answer choices are true.

Answer 22

D) All of these answer choices are true.

Question 23

σF functions as a(n) _________ during endospore formation.
A) transcription factor
B) anti-sigma factor
C) protease
D) RNase

Answer 23

A) transcription factor

σF (Sigma F) is an alternative sigma factor that directs the transcription of genes necessary for the early stages of endospore formation in Bacillus subtilis.

Question 24

When Spo0A is highly phosphorylated
A) heterocyst formation is initiated.
B) stalk formation is initiated.
C) endospore formation is initiated.
D) photosynthesis is initiated.

Answer 24

C) endospore formation is initiated.

Phosphorylated Spo0A (Spo0A~P) is the active form that triggers the initiation of endospore formation in Bacillus subtilis by regulating the expression of key genes.

Question 25

What is the function of heterocysts in cyanobacteria such as Anabaena?
A) nitrogen fixation
B) sexual reproduction
C) asexual reproduction
D) photosynthesis

Answer 25

A) nitrogen fixation

Heterocysts are specialized cells within cyanobacterial filaments where nitrogen fixation occurs, providing the filament with a source of reduced nitrogen.

Question 26

The major shape-determining factor in Bacteria is the protein
A) FtsZ.
B) crescentin.
C) MreB.
D) MinD.

Answer 26

C) MreB.

MreB is a bacterial actin homolog that plays a crucial role in determining and maintaining the cell shape of many bacteria, especially rod-shaped ones.

Question 27

In the process of binary fission in Bacteria, which action occurs first?
A) formation of the divisome
B) DNA replication
C) cell elongation
D) cytokinesis

Answer 27

B) DNA replication

The process of binary fission begins with the replication of the bacterial DNA, ensuring each daughter cell receives a complete genome.

Question 28

FtsZ is related to ________, an important protein involved in cell division.
A) actin
B) myosin
C) tubulin
D) collagen

Answer 28

C) tubulin

FtsZ is a bacterial protein that is structurally and functionally analogous to tubulin, which forms the mitotic spindle in eukaryotic cell division.

Question 29

FtsA is related to _______, an important cytoskeletal protein in eukaryotes.
A) actin
B) myosin
C) tubulin
D) collagen

Answer 29

A) actin

FtsA is associated with FtsZ and has been implicated in processes similar to those of actin in eukaryotes, though the primary relationship of FtsZ is with tubulin. However, given the options and focusing on cytoskeletal roles, the closest eukaryotic functional analogue provided in the options for a divisome component after FtsZ would mistakenly point towards actin for FtsA, though this is a stretch and more about divisome complex functionality.

Question 30

Endospore formation is stimulated when
A) bacterial growth ceases due to limitation of an essential nutrient.
B) the bacterium is undergoing binary fission.
C) bacteria are dividing exponentially.
D) nutrient levels rise.

Answer 30

A) bacterial growth ceases due to limitation of an essential nutrient.

Endospore formation is typically triggered in response to harsh environmental conditions, such as the lack of an essential nutrient, which halts bacterial growth.

Question 31

Proteins MinC, MinD, and MinE interact to
A) help guide FtsZ to the cell midpoint.
B) initiate peptidoglycan synthesis.
C) assist chromosome segregation.
D) determine cell shape.

Answer 31

A) help guide FtsZ to the cell midpoint.

The Min system (comprising MinC, MinD, and MinE) functions to prevent aberrant Z-ring formation by ensuring FtsZ is positioned at the cell midpoint for proper division.

Question 32

The curved-rod shape typical of Caulobacter is due to the protein(s)
A) crescentin.
B) MreB.
C) crescentin and MreB.
D) neither crescentin nor MreB.

Answer 32

A) crescentin.

Crescentin is a bacterially derived intermediate filament protein that is responsible for the characteristic curved or crescent shape of Caulobacter cells.

Question 33

Which of the following traits is NOT characteristic of the Caulobacter life cycle?
A) Cell division only occurs in the swarmer stage.
B) Cell division only occurs in the stalked cell stage.
C) Chromosome replication only occurs in the swarmer stage.
D) Chromosome replication and cell division only occurs in the stalked cell stage.

Answer 33

C) Chromosome replication only occurs in the swarmer stage.

In Caulobacter, chromosome replication is actually initiated in the stalked cell stage, not exclusively in the swarmer stage.

Question 34

Biofilm formation in Pseudomonas aeruginosa is triggered by _____ cell densities and repressed by ______ cell densities.
A) high; high
B) low; low
C) high; low
D) low; high

Answer 34

C) high; low

Biofilm formation in P. aeruginosa is indeed promoted at high cell densities (quorum sensing) and repressed or less favorable at low cell densities.

Question 35

Biofilm formation in Vibrio cholera is triggered by _____ cell densities and repressed by ______ cell densities.
A) high; high
B) low; low
C) high; low
D) low; high

Answer 35

D) low; high

This is somewhat counterintuitive based on the common quorum sensing model. However, for V. cholerae, biofilm formation can be initiated at lower cell densities, and high cell densities might signal a shift towards a more planktonic lifestyle or other behaviors, though this can depend heavily on environmental cues.

Question 36

What is the function of bactoprenol?
A) It is a hydrophobic alcohol that transports peptidoglycan precursors across the cytoplasmic membrane.
B) It is responsible for forming the peptide cross-links between muramic acid residues in adjacent glycan chains.
C) It triggers the recruitment of FtsZ and the initiation of the divisome.
D) It supplies the energy necessary for transpeptidation to occur.

Answer 36

A) It is a hydrophobic alcohol that transports peptidoglycan precursors across the cytoplasmic membrane.

Bactoprenol (also known as undecaprenol) serves as a carrier molecule, transporting peptidoglycan (cell wall) precursors across the bacterial cytoplasmic membrane.

Question 37

Shortage of key nutrients such as ________ results in transcription and secretion of a toxic protein that leads to cannibalization of neighboring cells of the same species.
A) magnesium
B) phosphate
C) calcium
D) iron

Answer 37

B) phosphate

While the question might imply a more general nutrient scarcity, in some bacteria, phosphate limitation can lead to the production of toxins that can kill neighboring cells, a form of cannibalism, to release nutrients.

Question 38

Heterocysts are specialized cells that undergo
A) oxidative phosphorylation.
B) photophosphorylation.
C) nitrogen fixation.
D) lysine decarboxylation

Answer 38

C) nitrogen fixation.

Heterocysts in cyanobacteria are the site of nitrogen fixation, converting atmospheric nitrogen (N2) into a usable form for the cell.

Question 39

Which of the following is NOT a function of DnaA in Caulobacter?
A) initiation of DNA replication
B) initiation of swarming
C) transcriptional regulation
D) All of these answer choices are functions of DnaA.

Answer 39

B) initiation of swarming

While DnaA is crucial for initiating DNA replication, its direct role is not typically described in terms of initiating swarming motility, which is more related to the regulation of flagellar genes and environmental sensing.

Question 40

Why is the presence of a cell wall significant from a clinical standpoint?
A) All types of cells have a cell wall, and it makes identification of the causative agent of disease difficult.
B) The cell wall protects microorganisms from destruction by the immune system.
C) Animal cells do not have cell walls, so antibiotics that target cell walls can selectively destroy invading microorganisms.
D) Only gram-negative Bacteria have cell walls.

Answer 40

C) Animal cells do not have cell walls, so antibiotics that target cell walls can selectively destroy invading microorganisms.

The presence of a cell wall in bacteria (absent in animal cells) provides a target for antibiotics (like penicillins) that can selectively kill bacterial cells without harming the host’s cells.

Question 41

Which of the following molecules functions as an intracellular signaling molecule during quorum sensing?
A) acylated homoserine lactones
B) hydrophilic lipids
C) quinones
D) proteorhodopsins

Answer 41

A) acylated homoserine lactones

While AHLs are primarily known as intercellular signaling molecules in quorum sensing, the question’s phrasing might cause confusion. However, the correct answer given the options and typical quorum sensing contexts would indeed relate to AHLs or similar molecules, but it’s worth noting the question’s focus on “intracellular,” which is not the typical context for AHLs.

Question 42

Dormancy is a result of all of the following EXCEPT
A) phenotypic heterogeneity.
B) ineffective efflux pumps.
C) TA modules.
D) the stringent response.

Answer 42

B) ineffective efflux pumps.

Dormancy in bacteria is often a result of various factors including phenotypic heterogeneity, the stringent response, and toxin-antitoxin (TA) modules. Ineffective efflux pumps, however, would more likely lead to increased susceptibility to antibiotics rather than directly causing dormancy.

Question 43

The purpose of hemimethylated DNA is to block chromosome replication.

Answer 43

FALSE

Hemimethylated DNA is a temporary state after DNA replication, where the new strand is not yet methylated. It’s involved in DNA mismatch repair and regulating replication initiation, not blocking replication.

Question 44

Plasmids are replicated in Escherichia coli using the Par system.

Answer 44

TRUE

The Par (partitioning) system is indeed responsible for ensuring plasmids are properly segregated during cell division in E. coli, often involving specific replication and partitioning mechanisms.

Question 45

PopZ plays a critical role in localizing proteins to the cell poles.

Answer 45

TRUE

PopZ is a protein in some bacteria (e.g., Caulobacter) that helps in organizing the cell pole and localizing certain proteins to this region, crucial for cell cycle progression and differentiation.

Question 46

The Par system is analogous to spindle fibers in eukaryotic cells.

Answer 46

TRUE

Both the Par system in prokaryotes and spindle fibers in eukaryotes are involved in ensuring genetic material is properly segregated during cell division, though they operate through vastly different mechanisms.

Question 47

In the Caulobacter life cycle, the role of swarmer cells is strictly for reproduction.

Answer 47

FALSE

Swarmer cells in Caulobacter are primarily involved in dispersal and finding a suitable location for attachment, after which they differentiate into stalked cells that can then reproduce.

Question 48

Biofilm formation is more likely to occur when Vibrio cholerae is found in low densities such as sea water.

Answer 48

TRUE

For V. cholerae, biofilm formation can indeed be favored at lower cell densities, such as those found in aquatic environments like sea water, as a strategy for survival and persistence.

Question 49

Multiple sigma factors are essential to induce the biosynthesis of endospores, consequently a complex regulatory mechanism such as this has a higher chance of mutation leading to incorrect functioning compared to a simple repression mechanism.

Answer 49

TRUE

The involvement of multiple sigma factors in endospore formation (e.g., σF, σE, σG, σK) does indeed imply a complex regulatory mechanism, which can be more prone to mutations affecting its function compared to simpler regulatory systems.

Question 50

Generation of new bacillus-shaped cells starts with one cell elongating and terminates when it splits into two separate bacilli.

Answer 50

TRUE

This accurately describes the process of binary fission in rod-shaped (bacillus) bacteria, which involves cell elongation followed by division into two daughter cells.

Question 51

The activity of MinC and MinD direct whether a bacterial cell will be coccoid or bacillus shaped.

Answer 51

FALSE

MinC and MinD are involved in determining the division site in bacteria, ensuring proper placement of the FtsZ ring, but they do not directly influence the overall cell shape (coccoid vs. bacillus).

Question 52

In fast-growing Escherichia coli cells, multiple replication forks of genomic DNA allows binary fission to occur before the genome has been fully duplicated.

Answer 52

TRUE

Rapidly growing E. coli can initiate new rounds of DNA replication before the previous one is complete, allowing for overlapping replication cycles and quicker cell division.

Question 53

Multiple sigma factors are essential to induce the formation of endospores.

Answer 53

TRUE

As mentioned earlier, the process of endospore formation in bacteria like Bacillus subtilis involves a cascade of gene expression controlled by a series of sigma factors (σF, σE, σG, σK).

Question 54

During elongation of a cell during binary fission, small gaps caused by transglycosylases are formed before cell membrane precursors can be inserted.

Answer 54

TRUE

The process of peptidoglycan synthesis during cell elongation indeed involves the creation of temporary gaps by transglycosylases, which are then filled with new peptidoglycan units.

Question 55

Antibiotic resistance can develop in a bacterium as a result of spontaneous mutation.

Answer 55

TRUE

Spontaneous mutations in bacterial genomes can indeed lead to the development of antibiotic resistance, as these mutations might alter the target of the antibiotic or enhance efflux pump activity.

Question 56

Natural antibiotics are produced by all bacterial genera.

Answer 56

FALSE

Not all bacterial genera produce natural antibiotics. This capability is more common in certain groups, such as Actinobacteria (e.g., Streptomyces) and some species of Bacillus.

Question 57

All members of the genus Pseudomonas respond similarly to c-di-GMP.

Answer 57

FALSE

While c-di-GMP is a crucial second messenger in many bacteria, including some Pseudomonas species, regulating processes like biofilm formation and motility, responses can vary significantly across different species within the genus.

Question 58

The spherical shape of Staphylococcus aureus is a result of MreB function.

Answer 58

FALSE

MreB is involved in maintaining the rod shape of bacteria. The spherical (coccoid) shape of Staphylococcus aureus is not a result of MreB function but rather the lack of a requirement for directional peptidoglycan synthesis to maintain a specific shape.

Question 59

Both crescentin and MreB play a role in formation of the vibrio-shaped bacterium Caulobacter.

Answer 59

FALSE

Crescentin is primarily responsible for the curved shape of Caulobacter, while MreB is more generally associated with rod-shaped bacteria and is not the primary determinant of Caulobacter’s vibrio shape.

Question 60

FtsZ is analogous to the protein tubulin in eukaryotic cells.

Answer 60

TRUE

FtsZ and tubulin share functional and structural similarities, as both form dynamic filaments (Z-ring in bacteria, microtubules in eukaryotes) crucial for cell division.

Question 61

In both cocci as well as rod-shaped cells, new peptidoglycan synthesis occurs in both directions from the central location of the FtsZ ring.

Answer 61

TRUE

This statement accurately describes the process of peptidoglycan synthesis during cell division in both coccoid and rod-shaped bacteria, where new cell wall material is inserted from the center (FtsZ ring) outward.

Question 62

Oxygenic phototrophs require the uptake of oxygen for the reactions of photosynthesis.

Answer 62

FALSE

Oxygenic phototrophs (like cyanobacteria and plants) produce oxygen as a byproduct of photosynthesis but do not require oxygen uptake for the photosynthetic process itself.

Question 63

Mobile resistance genes encode enzymes that inactivate an antibiotic by altering its structure.

Answer 63

TRUE

Mobile genetic elements can carry genes encoding enzymes (e.g., beta-lactamases) that modify antibiotics, rendering them ineffective against the bacterium.

Question 64

Unlike penicillin, methicillin targets an alternative penicillin binding protein called MecA in nonresistant Staphylococcus aureus.

Answer 64

FALSE

Methicillin (and other beta-lactams) targets the same set of penicillin-binding proteins (PBPs) as penicillin. Resistance in MRSA is due to the acquisition of the mecA gene, which encodes PBP2a (MecA), an alternative PBP with a low affinity for beta-lactams.

Question 65

MRSA strains synthesize MecA only in the presence of methicillin or other β-lactam antibiotics.

Answer 65

FALSE

MRSA strains constitutively express the mecA gene, producing PBP2a (MecA) regardless of the presence of methicillin or other beta-lactam antibiotics.

Question 66

Antibiotic-sensitive bacteria sometimes produce cells that are transiently resistant to multiple antibiotics.

Answer 66

TRUE

Persister cells are a subpopulation of bacteria that can survive exposure to antibiotics without being genetically resistant, providing a transient mechanism of survival.

Question 67

When Mycobacterium tuberculosis is in the dormant state it is still susceptible to antibiotics, but the rate of death is slower.

Answer 67

FALSE

Dormant M. tuberculosis is characterized by reduced susceptibility to many antibiotics, as the dormant state often involves changes in metabolism and structure that limit antibiotic efficacy.

Question 68

Persistence is a heritable trait.

Answer 68

FALSE

Persistence, as seen in persister cells, is generally not a heritable trait but rather a phenotypic state that certain cells within a population can enter and exit, influenced by various factors including environmental conditions.

Question 69

The toxin component of TA modules helps ensure survival during stressful growth conditions.

Answer 69

TRUE

Toxin-antitoxin (TA) systems are involved in various cellular processes, including programmed cell death (apoptosis-like processes) under stressful conditions, which can help the survival of the bacterial population by eliminating stressed or damaged cells.

Question 70

Free HipA toxin inhibits transcription.

Answer 70

FALSE

It is described in the context of causing the cell to remain in a dormant state, which implies an effect on cellular metabolism or growth rather than a direct inhibition of transcription.