Differentiate between primary productivity and secondary productivity.
Primary productivity = plants (photosynthesis); Secondary productivity = consumers (energy transfer).

Two important characteristics for estimating any population of animals and plants are \(\underline{\hspace{2cm}}\) and \(\underline{\hspace{2cm}}\) of individuals.
Demography is the study of factors that affect \(\underline{\hspace{2cm}}\) and \(\underline{\hspace{2cm}}\) patterns.