Question

Which one of the following statements about batch culture of microbes is NOT correct?

• A. Cells from stationary phase will show longer lag phase when inoculated in fresh growth medium compared to those collected from exponential phase.
• B. Death phase of culture is often exponential in nature.
• C. Stationary phase is the cryptic growth phase.
• D. The rate of generation of new cells during exponential growth phase is constant.

Hint:

Remember: In exponential growth, the rate of increase is proportional to population size, so it is not constant; only the doubling time remains constant.

Answer 1

The Correct Option is D

Step 1: Exponential phase. In this phase, the generation time (time required to double the population) is constant, but the rate of generation of new cells increases exponentially with population size. Thus, statement (D) is incorrect.
Step 2: Other options. (A) True — stationary-phase cells adapt slower, showing longer lag.
(B) True — death phase is often exponential (negative growth rate).
(C) True — stationary phase involves cell division balanced by cell death, also termed cryptic growth.
Therefore, the incorrect statement is (D).