- Life Sciences
a chemical messenger produced and released by a cell or a gland in one part of the body of the organism that affect cells in other parts of the organism. In essence, it is a chemical messenger that transports a signal from one cell to another. Only a small amount of hormone is required to alter cell metabolism. Hormones in animals are most often transported in the blood.
tough connective tissue found in conjunction with muscle, cartilage and bone.
the very cold zone in an ocean, dam or a lake, located below the range of effective light...
a graphical representation of the evolutionary relationship between taxonomic groups based on...