Question

The following graph show the growth of a bacterial culture. Which of the following statements about this graph are true?

a. In phase 3, some bacteria may be dividing.

b. Phase 2 is called as the lag phase and phase 1 is called as the log phase.

c. Phase 4 could be caused by the build-up of metabolic toxins.

d. Growth in phase 2 follows an exponential progression.

e. The fastest rate of growth is seen at the plateau, i.e., phase 3.

• A. a, b and c
• B. b and e
• C. a, c and d
• D. a and d
• E. b and d

Answer 1

Answer: (C)

a, c and d

The first phase of bacterial growth is a lag phase where no growth takes place. This is the phase when the bacterial cells are adapting to the new medium. The second phase is the log phase having faster growth due to the usage of the nutrients. The third phase is the stationary phase where the bacterial growth is constant. The fourth phase is the death phase due to the accumulation of toxins.

Thus, the correct answer is option C.