HUBS 2601 FINAL EXAM REVISION 100% VERIFIED
QUESTIONS AND ANSWER
Microbial diversity - ANS>> The variety of microorganisms, including bacteria, viruses, fungi, and
protozoa, classified by genetic, phenotypic, and ecological differences.
Microbial structure - ANS>> The physical makeup of a microbe, including cell wall, membrane,
organelles, and external features like flagella or pili.
Function of the bacterial cell wall - ANS>> Provides structural support and protection; prevents
osmotic lysis.
Difference between Gram-positive and Gram-negative bacterial cell walls - ANS>> Gram-positive has
thick peptidoglycan and no outer membrane; Gram-negative has thin peptidoglycan and an outer
membrane.
Role of the bacterial capsule - ANS>> Helps evade the immune system by preventing phagocytosis.
Function of bacterial flagella - ANS>> Provides motility for bacteria, allowing them to move toward
nutrients or away from harmful substances.
Pili and fimbriae - ANS>> Used for attachment to surfaces, biofilm formation, and sometimes
conjugation.
Bacterial binary fission - ANS>> A method of asexual reproduction where one bacterial cell divides into
two identical daughter cells.
Factors influencing bacterial growth rate - ANS>> Temperature, pH, oxygen, nutrients, and waste
products.
Bacterial growth curve - ANS>> A graphical representation of bacterial population growth over time in
four phases: lag, log, stationary, and death.
,Lag phase in bacterial growth - ANS>> The period where bacteria adapt to their environment but do
not divide rapidly.
Log phase in bacterial growth - ANS>> The period of rapid cell division and exponential growth.
Stationary phase in bacterial growth - ANS>> The phase where growth rate slows due to nutrient
depletion and waste accumulation.
Death phase in bacterial growth - ANS>> The phase where bacteria die at a faster rate than they
divide.
Chemostat - ANS>> A continuous culture system where nutrients are constantly supplied, and waste is
removed to maintain a steady state.
Bacterial metabolism - ANS>> The chemical processes used by bacteria to obtain energy and build
cellular components.
Difference between aerobic and anaerobic respiration in bacteria - ANS>> Aerobic uses oxygen as the
final electron acceptor; anaerobic uses other molecules like nitrate or sulfate.
Fermentation - ANS>> An anaerobic process where bacteria convert sugars into energy without an
electron transport chain.
Auxotrophs - ANS>> Bacteria that require specific nutrients for growth that they cannot synthesize
themselves.
Operon - ANS>> A cluster of genes in bacteria that are regulated together under a single promoter.
Horizontal gene transfer - ANS>> The movement of genetic material between bacteria, not inherited
from parent cells.
Transformation in bacteria - ANS>> Uptake of free DNA from the environment by bacteria.
, Transduction in bacteria - ANS>> Transfer of DNA from one bacterium to another via bacteriophages
(viruses).
Conjugation in bacteria - ANS>> Transfer of DNA between bacteria through direct cell-to-cell contact,
often via pili.
Plasmids - ANS>> Small, circular DNA molecules in bacteria that replicate independently of the
chromosome.
Transposons - ANS>> Mobile genetic elements that can move within and between DNA molecules.
Antibiotic resistance - ANS>> The ability of bacteria to resist the effects of antibiotics through genetic
changes.
Pathogenicity island - ANS>> A cluster of genes in bacteria that contribute to the ability to cause
disease.
Acquisition of pathogenicity islands - ANS>> Through horizontal gene transfer, such as conjugation,
transduction, or transformation.
Type III secretion systems - ANS>> Molecular syringes in bacteria that inject proteins into host cells to
manipulate their functions.
Type IV secretion systems - ANS>> Complex systems that transfer DNA or proteins to other bacteria or
host cells.
Quorum sensing - ANS>> A system of communication where bacteria release and detect chemical
signals to coordinate behavior.
Biofilms - ANS>> Communities of bacteria attached to surfaces, embedded in a self-produced matrix.
QUESTIONS AND ANSWER
Microbial diversity - ANS>> The variety of microorganisms, including bacteria, viruses, fungi, and
protozoa, classified by genetic, phenotypic, and ecological differences.
Microbial structure - ANS>> The physical makeup of a microbe, including cell wall, membrane,
organelles, and external features like flagella or pili.
Function of the bacterial cell wall - ANS>> Provides structural support and protection; prevents
osmotic lysis.
Difference between Gram-positive and Gram-negative bacterial cell walls - ANS>> Gram-positive has
thick peptidoglycan and no outer membrane; Gram-negative has thin peptidoglycan and an outer
membrane.
Role of the bacterial capsule - ANS>> Helps evade the immune system by preventing phagocytosis.
Function of bacterial flagella - ANS>> Provides motility for bacteria, allowing them to move toward
nutrients or away from harmful substances.
Pili and fimbriae - ANS>> Used for attachment to surfaces, biofilm formation, and sometimes
conjugation.
Bacterial binary fission - ANS>> A method of asexual reproduction where one bacterial cell divides into
two identical daughter cells.
Factors influencing bacterial growth rate - ANS>> Temperature, pH, oxygen, nutrients, and waste
products.
Bacterial growth curve - ANS>> A graphical representation of bacterial population growth over time in
four phases: lag, log, stationary, and death.
,Lag phase in bacterial growth - ANS>> The period where bacteria adapt to their environment but do
not divide rapidly.
Log phase in bacterial growth - ANS>> The period of rapid cell division and exponential growth.
Stationary phase in bacterial growth - ANS>> The phase where growth rate slows due to nutrient
depletion and waste accumulation.
Death phase in bacterial growth - ANS>> The phase where bacteria die at a faster rate than they
divide.
Chemostat - ANS>> A continuous culture system where nutrients are constantly supplied, and waste is
removed to maintain a steady state.
Bacterial metabolism - ANS>> The chemical processes used by bacteria to obtain energy and build
cellular components.
Difference between aerobic and anaerobic respiration in bacteria - ANS>> Aerobic uses oxygen as the
final electron acceptor; anaerobic uses other molecules like nitrate or sulfate.
Fermentation - ANS>> An anaerobic process where bacteria convert sugars into energy without an
electron transport chain.
Auxotrophs - ANS>> Bacteria that require specific nutrients for growth that they cannot synthesize
themselves.
Operon - ANS>> A cluster of genes in bacteria that are regulated together under a single promoter.
Horizontal gene transfer - ANS>> The movement of genetic material between bacteria, not inherited
from parent cells.
Transformation in bacteria - ANS>> Uptake of free DNA from the environment by bacteria.
, Transduction in bacteria - ANS>> Transfer of DNA from one bacterium to another via bacteriophages
(viruses).
Conjugation in bacteria - ANS>> Transfer of DNA between bacteria through direct cell-to-cell contact,
often via pili.
Plasmids - ANS>> Small, circular DNA molecules in bacteria that replicate independently of the
chromosome.
Transposons - ANS>> Mobile genetic elements that can move within and between DNA molecules.
Antibiotic resistance - ANS>> The ability of bacteria to resist the effects of antibiotics through genetic
changes.
Pathogenicity island - ANS>> A cluster of genes in bacteria that contribute to the ability to cause
disease.
Acquisition of pathogenicity islands - ANS>> Through horizontal gene transfer, such as conjugation,
transduction, or transformation.
Type III secretion systems - ANS>> Molecular syringes in bacteria that inject proteins into host cells to
manipulate their functions.
Type IV secretion systems - ANS>> Complex systems that transfer DNA or proteins to other bacteria or
host cells.
Quorum sensing - ANS>> A system of communication where bacteria release and detect chemical
signals to coordinate behavior.
Biofilms - ANS>> Communities of bacteria attached to surfaces, embedded in a self-produced matrix.
