Biology glossary

time during the Cambrian period (542–488 million years ago) when most of the animal phyla in existence today evolved

avoid detection by blending in with the background

microchannel that connects the lacunae and aids diffusion between cells

(cd) unit of measurement of luminous intensity (brightness)

branches and foliage of trees that form a layer of overhead coverage in a forest

smallest blood vessel that allows the passage of individual blood cells and the site of diffusion of oxygen and nutrient exchange

occurs because water molecules are attracted to charges on the inner surfaces of narrow tubular structures such as glass tubes, drawing the water molecules to the tubes' sides

large number of capillaries that converge to take blood to a particular organ or tissue

protein coating of the viral core

protein subunit that makes up the capsid

external structure that enables a prokaryote to attach to surfaces and protects it from dehydration

case of the sporangium in mosses

tentacle-like projection that is present in tusks shells to catch prey

molecule that forms when carbon dioxide binds to hemoglobin

biological macromolecule in which the ratio of carbon to hydrogen and to oxygen is 1:2:1; carbohydrates serve as energy sources and structural support in cells and form the a cellular exoskeleton of arthropods.