Chapter 6: Microbial Nutrition and Growth — Online MCQ Test
MICROBIOLOGY · CLASS 11th · Tamil Nadu State Board
Practice Chapter 6: Microbial Nutrition and Growth with a free chapter-wise online MCQ test.
This chapter covers: Exploring cellular metabolism this chapter details nutritional categories autotrophs heterotrophs microbial growth phases batch and continuous culture. Students examine environment....
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Chapter 6: Microbial Nutrition and Growth — Important Questions & Answers
Which organisms derive their carbon source from carbon dioxide?
- A. Autotrophs
- B. Heterotrophs
- C. Chemoorganotrophs
- D. Parasites
Answer: A. Autotrophs
Autotrophs are organisms that utilize inorganic carbon in the form of CO2 as their primary carbon source.
Autotrophs are organisms that utilize inorganic carbon in the form of CO2 as their primary carbon source.
The phase in bacterial growth where the rate of growth is equal to the rate of death is called:
- A. Lag phase
- B. Log phase
- C. Stationary phase
- D. Decline phase
Answer: C. Stationary phase
In the stationary phase, nutrient depletion and waste accumulation balance the growth rate, leading to no net population change.
In the stationary phase, nutrient depletion and waste accumulation balance the growth rate, leading to no net population change.
What happens to the microbial cell membrane at extremely low temperatures?
- A. It becomes too fluid
- B. It solidifies and prevents transport
- C. It ruptures due to ice crystals
- D. It increases enzyme activity
Answer: B. It solidifies and prevents transport
At low temperatures, membrane lipids solidify, reducing fluidity and hindering nutrient transport into the cell.
At low temperatures, membrane lipids solidify, reducing fluidity and hindering nutrient transport into the cell.
Why is the lag phase longer in old or damaged bacterial cultures?
- A. Cells are dividing too rapidly
- B. Cells need time to synthesize new enzymes for nutrient utilization
- C. The culture is already in the decline phase
- D. Oxygen is not required in the lag phase
Answer: B. Cells need time to synthesize new enzymes for nutrient utilization
When inoculated into new media, aged cells must repair damage and adapt their enzymatic machinery before synthesis and division occur.
When inoculated into new media, aged cells must repair damage and adapt their enzymatic machinery before synthesis and division occur.
A chemostat differs from a batch culture because in a chemostat:
- A. The population eventually dies
- B. The dilution rate is controlled to maintain steady-state growth
- C. Waste products accumulate in the medium
- D. It is used primarily for clinical diagnosis
Answer: B. The dilution rate is controlled to maintain steady-state growth
A chemostat allows for the precise control of the growth rate by balancing the inflow of media with the outflow of culture volume.
A chemostat allows for the precise control of the growth rate by balancing the inflow of media with the outflow of culture volume.