Question

Typhoid fever is caused by bacteria in contaminated food or drink. In 1903, an outbreak of typhoid fever in Ithaca, New York, killed almost 80 people. In addition, more than 1,000 Ithaca residents became sick with the disease. The population shares the public water source. Which type of limiting factor was involved in the typhoid outbreak that occurred in Ithaca?

a. density-independent factor
b. density-dependent factor
c. population-dependent factor
d. population-independent factor

Answer 1

The correct answer would be b. density-dependent factor.

Density-dependent factor is a limiting factor the effect of which depends on the number of individuals present in a population.

The more the population size the more effect it will produce.

Similarly, contaminated food and drink are the density-dependent limiting factor.

Overcrowding or large population size increases the effect of a disease which limit the growth of the population.

Answer 2

The type of limiting factor that was involved in the typhoid outbreak that occurred in Ithaca was density-dependent factor. Typhoid fever is still having outbreaks in 2016. The latest was in Zimbabwe. The correct answer is B.