biology-dictionary_11-06-2009

Invertebrate An animal without a backbone; invertebrates make up 95% of animal species. In vitro fertilization Fertilization of ...

J Jaws Either of two bony or cartilaginous structures that in most vertebrates form the framework of the mouth and hold the teet ...

Keratin One of a group of tough, fibrous proteins formed by certain epidermal tissues and especially abundant in skin, claws, ha ...

Koch's postulates A set of four criteria for determining whether a specific pathogen is the cause of a disease. Krebs cycle A ch ...

Latex The colorless or milky sap of certain trees and plants, such as the milkweed and the rubber tree, that hardens when expose ...

Leukotriene A type of prostaglandin produced by various white blood cells involved in the inflammatory and immune responses and ...

Ligament A sheet or band of tough, fibrous tissue connecting bones or cartilages at a joint or supporting an organ. Light micros ...

Lipid One of a family of compounds, including fats, phospholipids, and steroids, that are insoluble in water. Lipochondria / idi ...

Lungs The invaginated respiratory surfaces of terrestrial vertebrates, land snails, and spiders that connect to the atmosphere b ...

Lysosomes A membrane-enclosed bag of hydrolytic enzymes found in the cytoplasm of eukaryotic cells. Lymph vessel A tubular passa ...

Malignant Dangerous to health; characterized by progressive and uncontrolled growth (especially of a tumor) Malpighian tubule A ...

Matrix The nonliving component of connective tissue, consisting of a web of fibers embedded in homogeneous ground substance that ...

Megabase pairs One of the pairs of chemical bases joined by hydrogen bonds that connect the complementary strands of a DNA molec ...

Mendel's second law The principle, originated by Gregor Mendel, stating that when two or more characteristics are inherited, ind ...

Mesonephric excretory tube of the mesonephros; becomes the mesonephric duct and contributes in the adult to the vasa efferentia ...

Metamorphosis The resurgence of development in an animal larva that transforms it into a sexually mature adult. Metanephridium I ...

Micropyle A pore in the membrane covering the ovum of some animals through which a spermatozoon can enter. Microspore In plants, ...

Minimum viable population size (MVP) The smallest number of individuals needed to perpetuate a population. Missense mutation The ...

Molecule Two or more atoms held together by covalent bonds. Molting A process in arthropods in which the exoskeleton is shed at ...

Monophyletic Pertaining to a taxon derived from a single ancestral species that gave rise to no species in any other taxa. Monos ...