Columbia Encyclopedia

(Encyclopedia) piano or pianoforte, musical instrument whose sound is produced by vibrating strings struck by felt hammers that are controlled from a keyboard. The piano's earliest predecessor was the dulcimer. The ...

(Encyclopedia)  CE5 Ignition system ignition, apparatus for igniting a combustible mixture. The German engineer Nikolaus A. Otto, in his first gas engine, used flame ignition; another method was heating a metal t...

(Encyclopedia) in vitro fertilization vēˈtrō, vĭˈtrō [key] (IVF), technique for conception of a human embryo outside the mother's body. Several ova, or eggs, are removed from the mother's body and placed in sp...

(Encyclopedia) coral reefs, limestone formations produced by living organisms, found in shallow, tropical marine waters. In most reefs, the predominant organisms are stony corals, colonial cnidarians that secrete an...

(Encyclopedia)  CE5 Longitudinal cross section of a flower at the time of fertilization, showing a pollen grain and a pollen tube. flower, name for the specialized part of a plant containing the reproductive orga...

(Encyclopedia)  CE5 Urinary system urinary system, group of organs of the body concerned with excretion of urine, that is, water and the waste products of metabolism. In humans, the kidneys are two small organs s...

(Encyclopedia)  CE5 Development of the human embryo embryo ĕmˈbrēō [key], name for the developing young of an animal or plant. In its widest definition, the embryo is the young from the moment of fertilizatio...

(Encyclopedia)  CE5 Schematic diagram of a computer system: Data flow is indicated by solid lines; control signals are indicated by dashed lines. computer, device capable of performing a series of arithmetic or l...

(Encyclopedia) marine biology, study of ocean plants and animals and their ecological relationships. Marine organisms may be classified (according to their mode of life) as nektonic, planktonic, or benthic. Nektonic...

(Encyclopedia) mosquito məskēˈtō [key], small, long-legged insect of the order Diptera, the true flies. The females of most species have piercing and sucking mouth parts and apparently they must feed at least on...