modern birds

excretory structures found in annelids

pore found at the end of nephridia

functional unit of the kidney

part of the ocean that extends from low tide to the edge of the continental shelf

energy content available to the organisms of the next trophic level

measurement of the energy accumulation within an ecosystem, calculated as the total amount of carbon fixed per year minus the amount that is oxidized during cellular respiration

energy that remains in the primary producers after accounting for the organisms’ respiration and heat loss

measure of the ability of a trophic level to convert the energy it receives from the previous trophic level into biomass

stimulation of endocrine glands by the nervous system

tube-like structure that forms from the ectoderm and gives rise to the brain and spinal cord

study of the biology of the nervous system

nervous system disorder characterized by the progressive loss of neurological functioning, usually caused by neuron death

specialized cell that can receive and transmit electrical and chemical signals

chemical ligand that carries a signal from one nerve cell to the next