engulfment of one cell within another such that the engulfed cell survives, and both cells benefit; the process responsible for the evolution of mitochondria and chloroplasts in eukaryotes

theory that states that eukaryotes may have been a product of one cell engulfing another, one living within another, and evolving over time until the separate cells were no longer recognizable as such

animal capable of maintaining a relatively constant internal body temperature

allocation of energy resources for body maintenance, reproduction, and parental care

segment of DNA that is upstream, downstream, perhaps thousands of nucleotides away, or on another chromosome that influence the transcription of a specific gene

coelom formed by fusion of coelomic pouches budded from the endodermal lining of the archenteron

mesoderm of deuterostomes develops as pouches that are pinched off from endodermal tissue, cavity contained within the pouches becomes coelom

a system's total energy

measure of randomness or disorder within a system

change in the environment caused by natural disasters or human activities

catalyst in a biochemical reaction that is usually a complex or conjugated protein.

cell-surface receptor with intracellular domains that are associated with membranebound enzymes

leukocyte that responds to parasites and is involved in the allergic response

cell that lines fluid-filled ventricles of the brain and the central canal of the spinal cord; involved in production of cerebrospinal fluid

outermost tissue layer of the heart