Microbial Growth and Reproduction MCQs

1. : 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

2. : 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

3. : What is the term used to describe the process where microbial cells divide by binary fission?
(A) Conjugation
(B) Budding
(C) Fragmentation
(D) Fission

4. : Which factor does NOT affect the rate of microbial growth?
(A) Temperature
(B) pH
(C) Oxygen availability
(D) Color of the growth medium

5. : 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

6. : 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

7. : What is the primary method of cell division for bacteria?
(A) Binary fission
(B) Mitosis
(C) Meiosis
(D) Budding

8. : 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

9. : 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

10. : What is the term for microorganisms that thrive in extremely hot environments, such as hot springs?
(A) Psychrophiles
(B) Mesophiles
(C) Thermophiles
(D) Halophiles

11. : Which process involves the transfer of genetic material between bacterial cells through direct contact?
(A) Transformation
(B) Transduction
(C) Conjugation
(D) Replication

12. : 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

13. : 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

14. : 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

15. : 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

16. : 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