sweat gland

clade of protostomes that exhibit exoskeletal molting (ecdysis)

phylum of deuterostomes with spiny skin; exclusively marine organisms

(also, Eltonian pyramid) graphical representation of different trophic levels in an ecosystem based of organism numbers, biomass, or energy content

study of interaction between living things and their environment

all the living things in a particular area together with the abiotic, nonliving parts of that environment

community of living organisms and their interactions with their abiotic environment

variety of ecosystems

variety of ecosystems

study of the changes in ecosystem structure caused by changes in the environment or internal forces

human benefits and services provided by natural ecosystems

mycorrhizal fungi that surround the roots with a mantle and have a Hartig net that extends into the roots between cells

mycorrhizae in which the fungal hyphae do not penetrate the root cells of the plant

animal incapable of maintaining a relatively constant internal body temperature

geological period (630–542 million years ago) when the oldest definite multicellular organisms with tissues evolved