MIC 102 EXAM 1 QUESTIONS & ANSWERS
Which type of cell is most susceptible to osmotic lysis in an environment with a very low
concentration of solutes (hypotonic)? - Answers -Mycoplasma
Which of the following cellular structures self-assemble (purified monomers can
assemble into the structure without added factors or the input of energy)? - Answers -
Flagellar filament
Phospholipid bilayer
S layer
mycoplasma - Answers -only prokaryotic group listed that do not have a cell wall to
resist high osmotic pressure caused by water moving into the solute-rich cell
While Mycoplasma are highly successful inside the relatively isotonic environment
inside a host's body, they do not fare well in hypotonic environments or culture media.
how does phospholipid bilayer assemble? - Answers -phospholipid nonpolar tails are
attracted to each other to escape the hydrophilic environment surrounding them
how does flagellar filament assemble? - Answers -Flagellin aggregates spontaneously
at the tip of
the flagellar filament during flagellar assembly
how does the S layer assemble? - Answers -The S-layer is a lattice of a single protein
that will self-assemble into highly-ordered arrays
how do pili assemble? - Answers -built of monomers of the protein pilin that are added
to the base of the pilus filament
What distinguishes an organelle (such as a mitochrondrion or chloroplast) from a
carboxysome or enterosome? - Answers -Organelles may contain DNA
carboxysomes - Answers -protein-enclosed compartments where bacteria concentrate
the enzymes and substrates forcarbon fixation
enterosomes - Answers -protein-enclosed compartments where bacteria concentrate
the enzymes and substrates for propanediol and ethanolamine metabolism
DNA may be observed in which forms inside Bacterial cells? - Answers -Circular
chromosomes
what is bacterial DNA like? - Answers -single circular chromosome bound by DNA-
condensing proteins
, Positively-charged cations in the cytoplasm reduce the electrostatic repulsion of
negatively-charged DNA and allow its condensation into higher-ordered loops and
supercoiled structures
Bacteria may also have circular plasmids, which encode functions not essential for
survival (note: a cell may be "cured" of a plasmid but never of a chromosome)
T/F:
Only prokaryotes can transcribe and translate a gene at the same time. - Answers -true
Why can't eukaryotes transcribe and translate a gene at the same time? - Answers -
transcription and translation are separated in time and space: transcription can only
happen inside the nucleus while translation takes place in the cytoplasm or endoplasmic
reticulum
Why can prokaryotes transcribe and translate a gene at the same time? - Answers -
they do not have a membrane enclosing their DNA, DNA replication machinery, RNA
polymerase, and ribosomes can all access the DNA/RNA at the same time and place
Which of the following are NOT influenced by cell size? - Answers -Presence of a
phospholipid membrane
all cellular organisms have phospholipid membrane
Which of the following are influenced by cell size? - Answers -Type of microscopy used
to image cells
Acquisition of nutrients from the environment
Microbial growth rate (how quickly they replicate)
Surface area/volume ratio
Which statement provides evidence that the Eukarya lineage arose by the "ingestion" of
an ancestral bacterium by an ancestral archaeaon (cell from Archaea lineage)? -
Answers -Eukaryotic DNA replication and transcription enzymes are most similar to the
the equivalent enzymes in modern Archaea
T/F:
All cellular organisms grow best at 37oC although some extremophiles can tolerate
much higher or lower temperatures. - Answers -false
Extremophiles are highly adapted to the environments they are found in and would find
"normal" human temperatures incompatible with survival and/or growth
Which molecule is NOT a constituent of the gram-negative bacterial envelope? -
Answers -Lipoteichoic acid
Which molecule is a constituent of the gram-negative bacterial envelope? - Answers -
Lipopolysaccharide
Periplasm
Peptidoglycan
Which type of cell is most susceptible to osmotic lysis in an environment with a very low
concentration of solutes (hypotonic)? - Answers -Mycoplasma
Which of the following cellular structures self-assemble (purified monomers can
assemble into the structure without added factors or the input of energy)? - Answers -
Flagellar filament
Phospholipid bilayer
S layer
mycoplasma - Answers -only prokaryotic group listed that do not have a cell wall to
resist high osmotic pressure caused by water moving into the solute-rich cell
While Mycoplasma are highly successful inside the relatively isotonic environment
inside a host's body, they do not fare well in hypotonic environments or culture media.
how does phospholipid bilayer assemble? - Answers -phospholipid nonpolar tails are
attracted to each other to escape the hydrophilic environment surrounding them
how does flagellar filament assemble? - Answers -Flagellin aggregates spontaneously
at the tip of
the flagellar filament during flagellar assembly
how does the S layer assemble? - Answers -The S-layer is a lattice of a single protein
that will self-assemble into highly-ordered arrays
how do pili assemble? - Answers -built of monomers of the protein pilin that are added
to the base of the pilus filament
What distinguishes an organelle (such as a mitochrondrion or chloroplast) from a
carboxysome or enterosome? - Answers -Organelles may contain DNA
carboxysomes - Answers -protein-enclosed compartments where bacteria concentrate
the enzymes and substrates forcarbon fixation
enterosomes - Answers -protein-enclosed compartments where bacteria concentrate
the enzymes and substrates for propanediol and ethanolamine metabolism
DNA may be observed in which forms inside Bacterial cells? - Answers -Circular
chromosomes
what is bacterial DNA like? - Answers -single circular chromosome bound by DNA-
condensing proteins
, Positively-charged cations in the cytoplasm reduce the electrostatic repulsion of
negatively-charged DNA and allow its condensation into higher-ordered loops and
supercoiled structures
Bacteria may also have circular plasmids, which encode functions not essential for
survival (note: a cell may be "cured" of a plasmid but never of a chromosome)
T/F:
Only prokaryotes can transcribe and translate a gene at the same time. - Answers -true
Why can't eukaryotes transcribe and translate a gene at the same time? - Answers -
transcription and translation are separated in time and space: transcription can only
happen inside the nucleus while translation takes place in the cytoplasm or endoplasmic
reticulum
Why can prokaryotes transcribe and translate a gene at the same time? - Answers -
they do not have a membrane enclosing their DNA, DNA replication machinery, RNA
polymerase, and ribosomes can all access the DNA/RNA at the same time and place
Which of the following are NOT influenced by cell size? - Answers -Presence of a
phospholipid membrane
all cellular organisms have phospholipid membrane
Which of the following are influenced by cell size? - Answers -Type of microscopy used
to image cells
Acquisition of nutrients from the environment
Microbial growth rate (how quickly they replicate)
Surface area/volume ratio
Which statement provides evidence that the Eukarya lineage arose by the "ingestion" of
an ancestral bacterium by an ancestral archaeaon (cell from Archaea lineage)? -
Answers -Eukaryotic DNA replication and transcription enzymes are most similar to the
the equivalent enzymes in modern Archaea
T/F:
All cellular organisms grow best at 37oC although some extremophiles can tolerate
much higher or lower temperatures. - Answers -false
Extremophiles are highly adapted to the environments they are found in and would find
"normal" human temperatures incompatible with survival and/or growth
Which molecule is NOT a constituent of the gram-negative bacterial envelope? -
Answers -Lipoteichoic acid
Which molecule is a constituent of the gram-negative bacterial envelope? - Answers -
Lipopolysaccharide
Periplasm
Peptidoglycan
