The oak tree pathogen Phytophthora ramorum has migrated 650 km in ten years. West Nile virus spread from New York State to 46 others states in five years. The difference in the rate of spread is probably related to
A)how lethal each pathogen is.
B)the mobility of their hosts.
C)the fact that viruses are very small.
D)innate resistance.
E)dormancy viability.

Question

Quizplus · Accepted Answer

The mobility of the hosts plays a crucial role in the rate of spread of a pathogen. Phytophthora ramorum infects oak tree and other forest species, which are relatively immobile, while West Nile virus infects birds, which are highly mobile and can spread the disease across a larger geographic area in a shorter time. Therefore, B is the best choice.

The Oak Tree Pathogen Phytophthora Ramorum Has Migrated 650 Km