Mortality is best described as which of the following?

Mortality is best described as which of the following?

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

Answer: (B)

Mortality is reflected in the phase where cells decline in number because death exceeds new cell formation. In a closed growth system, after nutrients are depleted and waste builds up, cells can no longer sustain growth, and many die, so the population curves downward—that's the death phase. The other phases describe different situations: lag is a period of adaptation with little growth, the log phase is rapid exponential growth, and the stationary phase is when growth slows to a stop because production and loss are balanced. So mortality corresponds to the death phase, the decline in viability of the culture.

Mortality is reflected in the phase where cells decline in number because death exceeds new cell formation. In a closed growth system, after nutrients are depleted and waste builds up, cells can no longer sustain growth, and many die, so the population curves downward—that's the death phase. The other phases describe different situations: lag is a period of adaptation with little growth, the log phase is rapid exponential growth, and the stationary phase is when growth slows to a stop because production and loss are balanced. So mortality corresponds to the death phase, the decline in viability of the culture.