Which statement about exponential growth is true?

Which statement about exponential growth is true?

• A. It occurs in Gram-positive bacteria only
• B. It lasts indefinitely
• C. It is characterized by rapid reproduction, with doubling time about 20 minutes
• D. It leads to immediate cell death

Answer: (C)

Exponential growth means the population increases at a rate proportional to its size, so it accelerates as numbers get larger. In microbes, this shows up as a rapid doubling of the population under optimal conditions, often with a doubling time on the order of tens of minutes. Saying it has a doubling time of about 20 minutes captures that rapid, consistent reproduction seen during the log phase of growth. This phase isn’t infinite—resources, space, and waste buildup will eventually slow growth and shift the culture to a stationary or death phase. It isn’t limited to Gram-positive bacteria; many bacteria (both Gram-positive and Gram-negative) can undergo exponential growth when conditions are right. It also doesn’t imply immediate cell death; rather, reproduction outpaces death during this period.

Exponential growth means the population increases at a rate proportional to its size, so it accelerates as numbers get larger. In microbes, this shows up as a rapid doubling of the population under optimal conditions, often with a doubling time on the order of tens of minutes. Saying it has a doubling time of about 20 minutes captures that rapid, consistent reproduction seen during the log phase of growth. This phase isn’t infinite—resources, space, and waste buildup will eventually slow growth and shift the culture to a stationary or death phase. It isn’t limited to Gram-positive bacteria; many bacteria (both Gram-positive and Gram-negative) can undergo exponential growth when conditions are right. It also doesn’t imply immediate cell death; rather, reproduction outpaces death during this period.