Which factor do pathogens need in order to grow?

Which factor do pathogens need in order to grow?

• A. Time
• B. Temperature
• C. Oxygen
• D. Moisture

Answer: (A)

Growth of pathogens happens as they replicate, which takes time. Cellular division isn’t instantaneous—populations increase only after a certain period, known as generation time. Even when temperature, moisture, and oxygen are favorable, you still need time for multiple rounds of replication to occur, so growth can be observed. Time sets the window during which the other conditions can allow growth to proceed. Remember that temperature, moisture, and oxygen are also essential: the environment must be right for growth to happen at all, and these factors largely determine how fast growth occurs. But without any elapsed time, there’s no increase in numbers, so time is the fundamental factor required for growth to take place.

Growth of pathogens happens as they replicate, which takes time. Cellular division isn’t instantaneous—populations increase only after a certain period, known as generation time. Even when temperature, moisture, and oxygen are favorable, you still need time for multiple rounds of replication to occur, so growth can be observed. Time sets the window during which the other conditions can allow growth to proceed.

Remember that temperature, moisture, and oxygen are also essential: the environment must be right for growth to happen at all, and these factors largely determine how fast growth occurs. But without any elapsed time, there’s no increase in numbers, so time is the fundamental factor required for growth to take place.