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