Organisms that help pollinate plants is an example of what type of ecosystem service. 

Biodiversity increases as you move away from the equator. 

Earthquakes are an example of a density-dependent factor. 

A stationary population pyramid: 

The most important reservoir for phosphorus is the soil. 

The fire salamander can squirt a nerve toxin from glands on its back to deter predators. This is an example of: 

On earth, deserts are found at: 

During logistic growth, the rate of increase: 

To calculate the population growth rate (r), you need to know: 

The force most associated with injury to the MCL is: