Which growth phase is characterized by rapid replication and doubling times of about 20 minutes?

Which growth phase is characterized by rapid replication and doubling times of about 20 minutes?

• A. Lag Phase
• B. Death Phase
• C. Stationary Phase
• D. Exponential Phase

Answer: (D)

Exponential growth is when cells divide rapidly and maintain a constant doubling time. With abundant nutrients and optimal conditions, DNA replication and cell division proceed in a coordinated way, so the population increases by a stable factor each generation—often around 20 minutes for many bacteria under ideal conditions. This brisk, steady expansion is the hallmark of the exponential phase. In contrast, the lag phase is a period of adjustment before division begins, the stationary phase occurs when nutrients become limiting and growth halts, and the death phase is when more cells die than are produced. So the rapid replication and roughly 20-minute doubling time point to the exponential phase.

Exponential growth is when cells divide rapidly and maintain a constant doubling time. With abundant nutrients and optimal conditions, DNA replication and cell division proceed in a coordinated way, so the population increases by a stable factor each generation—often around 20 minutes for many bacteria under ideal conditions. This brisk, steady expansion is the hallmark of the exponential phase. In contrast, the lag phase is a period of adjustment before division begins, the stationary phase occurs when nutrients become limiting and growth halts, and the death phase is when more cells die than are produced. So the rapid replication and roughly 20-minute doubling time point to the exponential phase.