Which factor is density-dependent?

Which factor is density-dependent?

• A. Storms
• B. Disease transmission
• C. Drought
• D. Heat waves

Answer: (B)

Density-dependent factors are those whose impact on a population grows as the number of individuals increases. Disease transmission fits this idea because the more hosts packed in an area, the more opportunities there are for contacts and for a pathogen to spread. As population density rises, the transmission rate typically goes up, leading to larger or more rapid outbreaks, and as density falls, transmission slows down. In contrast, storms, drought, and heat waves are density-independent. Their occurrence and severity depend on weather and climate conditions rather than how many organisms are present, so their effects can hit small and large populations similarly, even though the absolute number affected may differ.

Density-dependent factors are those whose impact on a population grows as the number of individuals increases. Disease transmission fits this idea because the more hosts packed in an area, the more opportunities there are for contacts and for a pathogen to spread. As population density rises, the transmission rate typically goes up, leading to larger or more rapid outbreaks, and as density falls, transmission slows down.

In contrast, storms, drought, and heat waves are density-independent. Their occurrence and severity depend on weather and climate conditions rather than how many organisms are present, so their effects can hit small and large populations similarly, even though the absolute number affected may differ.