During which growth phase is the population size constant, cells metabolically active, and growth minimal?

• A. Log
• B. Death
• C. Lag
• D. Stationary

Answer: (C)

The stationary phase is when the population size stays roughly constant because the rate of new cell formation balances cell death, yet the cells remain metabolically active and growth is minimal. As nutrients become limited and waste products accumulate, division slows to a halt, but cells stay alive and shift their metabolism toward maintenance, stress responses, and resource recycling to survive. This contrasts with the lag phase, where cells are adapting with little division; the log phase, where growth is rapid; and the death phase, where death outpaces formation and the population declines.