To recycle nutrients, an ecosystem must have, at a minimum, _____.

Copernicus proposed a heliocentric model for the solar system primarily because ________.

Ddt, dde, pcbs, and pbdes are all ________.

Industrial ecologists ________.

The evolution of eukaryotic cells most likely involved _____.

Uniform spacing patterns in plants such as the creosote bush are most often associated with _____.

Atp contains a large amount of energy because _____.

At some time during their life cycles, bryophytes make _____.

As the glomerular filtrate is formed, it flows from the bowman's capsule into the __________.

Arthropod exoskeletons and mollusc shells both ________.

Archaea that "eat" methane are considered to be _____.