Which statement correctly describes how nitrogen in the soil returns to the atmosphere?
A. Soil bacteria converts usable nitrogen into nitrogen gas.
B. Plants convert usable nitrogen into nitrogen gas.
C. Nitrogen-fixing bacteria in plant roots convert usable nitrogen into nitrogen gas.
D. Lightning strikes the soil converting the nitrogen in the soil into nitrogen gas.

Match the following terms and definitions. 1. species that are adapted to live in equilibrium at carrying capacity population density 2. population growth that reaches equilibrium and carrying capacity population 3. death rate mortality 4. birth rate k-selected 5. a group of interacting individuals of the same species within the same geographic area natality 6. the number of organisms living in a particular area logistic growth