BIOL 3407 Lecture Exam 1 Questions With Complete
Solutions
Are viruses considered to be alive? Correct Answers No, they
do not replicate outside of a host cell
Are viruses inert? Correct Answers Yes, they are unable to
move and nonreactive outside of host cell
Does archaea contain peptidoglycan? Correct Answers No
How are bacteria cell walls differentiated? Correct Answers
stain method developed in 1884 by Hans christian gram
seperates microbes into one of two classes
How are growth characteristics determined in bacteria? Correct
Answers temperature, nutrients
How are the four causes and effects proven in Koch's
postulates? Correct Answers - suspected microbe is identified
in every person with the disease, but not those without illness
- pure culture of suspected microbe is obtained
- experimental inoculation of suspected microbe into a healthy
test host causes the same illness
- suspected microbe is recovered from the experimentally
inoculated host organism
How can nutrients get through cell walls in bacteria? Correct
Answers gram-positive peptidoglycan layer has large pores
throughout matrix, gram-negative has porin and TonB proteins
in its outer membrane to transfer molecules into periplasmic
,space (active transport mechanisms move molecule into
cytoplasm)
How can the PM be used for capturing energy? Correct
Answers embedded electron transport chains help create the
proton motive force (used for respiration, photosynthesis, derive
energy for motion; flagella)
How can the PM hold sensory systems? Correct Answers
proteins in PM used to detect environmental changes, cell can
use detected changes to alter gene expression to respond
How did microbial life arise on earth? Correct Answers RNA
and micelles formed, they came together into a primitive cell
using RNA for storing genetic info and coding, primitive cells
eventually changed from using RNA to DNA instead for storage
of genetic information.
How do bacterial cells produce more runs to move in a specific
direction? Correct Answers using chemoreceptor proteins to
sense changes in concentrations of attractants or repellents
How do capsules help bacteria form biofilms? Correct Answers
provide protection and enhances survivability in harsh
environments, examples include dental plaque and mold in
bathroom
How do structures on the surface of bacterial cells allow for
complex interactions with the environment? Correct Answers
motility from flagella: spiral, hollow, rigid filaments extending
, from the cell surface; locations and number vary from species to
species
How does H2O cross the PM to get into a cell? Correct
Answers aquaporin protein channels
How does O2 and CO2 cross the PM to get into a cell? Correct
Answers small and can diffuse across readily
How does polymerization occur in nonflagellar motility?
Correct Answers polymerization of actin in host cells for
propulsion of bacteria into adjacent cells (Shigella dysenteriae,
Listeria monocytogenes)
How does the spinning forces of flagella work in bacteria?
Correct Answers energy to spin derived from PMF, spinning
one way produces a "run" (directional movement) while
spinning the other way produces a "tumble" (nondirectional
movement)
How does the type III secretion system work? Correct Answers
newly synthesized polypeptides in the cytoplasm are delivered
to the secretory channel in the PM. they pass through a gated
channel created by integral membrane proteins, then continue
through hollow syringe (capable of penetrating the surface of
host cells and injecting various cytotoxins)
How is a sex pilus used on bacterial cell surface? Correct
Answers used for conjugation (sending DNA plasmid from one
cell to another)
Solutions
Are viruses considered to be alive? Correct Answers No, they
do not replicate outside of a host cell
Are viruses inert? Correct Answers Yes, they are unable to
move and nonreactive outside of host cell
Does archaea contain peptidoglycan? Correct Answers No
How are bacteria cell walls differentiated? Correct Answers
stain method developed in 1884 by Hans christian gram
seperates microbes into one of two classes
How are growth characteristics determined in bacteria? Correct
Answers temperature, nutrients
How are the four causes and effects proven in Koch's
postulates? Correct Answers - suspected microbe is identified
in every person with the disease, but not those without illness
- pure culture of suspected microbe is obtained
- experimental inoculation of suspected microbe into a healthy
test host causes the same illness
- suspected microbe is recovered from the experimentally
inoculated host organism
How can nutrients get through cell walls in bacteria? Correct
Answers gram-positive peptidoglycan layer has large pores
throughout matrix, gram-negative has porin and TonB proteins
in its outer membrane to transfer molecules into periplasmic
,space (active transport mechanisms move molecule into
cytoplasm)
How can the PM be used for capturing energy? Correct
Answers embedded electron transport chains help create the
proton motive force (used for respiration, photosynthesis, derive
energy for motion; flagella)
How can the PM hold sensory systems? Correct Answers
proteins in PM used to detect environmental changes, cell can
use detected changes to alter gene expression to respond
How did microbial life arise on earth? Correct Answers RNA
and micelles formed, they came together into a primitive cell
using RNA for storing genetic info and coding, primitive cells
eventually changed from using RNA to DNA instead for storage
of genetic information.
How do bacterial cells produce more runs to move in a specific
direction? Correct Answers using chemoreceptor proteins to
sense changes in concentrations of attractants or repellents
How do capsules help bacteria form biofilms? Correct Answers
provide protection and enhances survivability in harsh
environments, examples include dental plaque and mold in
bathroom
How do structures on the surface of bacterial cells allow for
complex interactions with the environment? Correct Answers
motility from flagella: spiral, hollow, rigid filaments extending
, from the cell surface; locations and number vary from species to
species
How does H2O cross the PM to get into a cell? Correct
Answers aquaporin protein channels
How does O2 and CO2 cross the PM to get into a cell? Correct
Answers small and can diffuse across readily
How does polymerization occur in nonflagellar motility?
Correct Answers polymerization of actin in host cells for
propulsion of bacteria into adjacent cells (Shigella dysenteriae,
Listeria monocytogenes)
How does the spinning forces of flagella work in bacteria?
Correct Answers energy to spin derived from PMF, spinning
one way produces a "run" (directional movement) while
spinning the other way produces a "tumble" (nondirectional
movement)
How does the type III secretion system work? Correct Answers
newly synthesized polypeptides in the cytoplasm are delivered
to the secretory channel in the PM. they pass through a gated
channel created by integral membrane proteins, then continue
through hollow syringe (capable of penetrating the surface of
host cells and injecting various cytotoxins)
How is a sex pilus used on bacterial cell surface? Correct
Answers used for conjugation (sending DNA plasmid from one
cell to another)
