By: Prof. Dr. Fazal Rehman | Last updated: July 26, 2024
Which phase of microbial growth is characterized by cell enlargement and metabolic activity but no increase in cell number?
A) Lag phase
B) Log phase
C) Stationary phase
D) Death phase Answer: A) Lag phase
During which phase of microbial growth does the number of new cells produced equal the number of cells dying?
A) Lag phase
B) Log phase
C) Stationary phase
D) Death phase Answer: C) Stationary phase
What is the term used to describe the process where microbial cells divide by binary fission?
A) Conjugation
B) Budding
C) Fragmentation
D) Fission Answer: D) Fission
Which factor does NOT affect the rate of microbial growth?
A) Temperature
B) pH
C) Oxygen availability
D) Color of the growth medium Answer: D) Color of the growth medium
What is the term for the maximum population density that an environment can support for a given microorganism?
A) Carrying capacity
B) Lag phase
C) Death phase
D) Log phase Answer: A) Carrying capacity
Which type of microbial growth medium is designed to selectively support the growth of a particular microorganism while inhibiting others?
A) Differential medium
B) Enrichment medium
C) Selective medium
D) General-purpose medium Answer: C) Selective medium
What is the primary method of cell division for bacteria?
A) Binary fission
B) Mitosis
C) Meiosis
D) Budding Answer: A) Binary fission
In which phase of microbial growth are cells dividing at the maximum rate, leading to exponential growth?
A) Lag phase
B) Log phase
C) Stationary phase
D) Death phase Answer: B) Log phase
Which of the following conditions can lead to the end of the stationary phase of microbial growth?
A) Nutrient depletion
B) Increase in temperature
C) Increased oxygen availability
D) Decrease in waste products Answer: A) Nutrient depletion
What is the term for microorganisms that thrive in extremely hot environments, such as hot springs?
A) Psychrophiles
B) Mesophiles
C) Thermophiles
D) Halophiles Answer: C) Thermophiles
Which process involves the transfer of genetic material between bacterial cells through direct contact?
A) Transformation
B) Transduction
C) Conjugation
D) Replication Answer: C) Conjugation
What is the primary method by which bacteria in a biofilm communicate with each other?
A) Chemical signaling
B) Direct cell-to-cell contact
C) Genetic recombination
D) Spore formation Answer: A) Chemical signaling
In a closed system of microbial growth, what usually limits the population growth in the long term?
A) Nutrient availability
B) Oxygen levels
C) Temperature
D) Waste accumulation Answer: D) Waste accumulation
Which of the following methods is commonly used to measure microbial growth in a liquid culture?
A) Direct microscopic count
B) Turbidity measurement
C) Plate count
D) Gram staining Answer: B) Turbidity measurement
What is the term for a microbial growth medium that provides all the necessary nutrients for the growth of a wide range of microorganisms?
A) Selective medium
B) Differential medium
C) Enrichment medium
D) General-purpose medium Answer: D) General-purpose medium
Which phase of microbial growth is characterized by a high rate of cell death due to depletion of nutrients and accumulation of toxic waste products?
A) Lag phase
B) Log phase
C) Stationary phase
D) Death phase Answer: D) Death phase
