|
Zoology |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
"Animal" is derived from the Latin anima, in the sense of vital breath (not related with soul). Animalia is from the Latin animalis. The scientific study of animals is called zoology and is a sub-discipline of biology, the study of all living things. The study of their relation to their environment and of their distribution is animal ecology. Animals are living things that need to eat, and feed on other living things (or dead things that once were living). Plants don't 'eat' but make their own food. Plants and algae characteristically manufacture their food from inorganic substances (usually by photosynthesis); animals must secure food already organized into organic substances. They are dependent upon photosynthetic organisms, which provide oxygen as a byproduct and are the ultimate source of all their food. In most forms there is a distinct alimentary canal or digestive system. There are 3 distinct kinds of animals:
Also, scavengers eat dead animals (e.g. T-rex, hyenas), and parasites live in or on other living things (e.g. ticks). Animals breathe, taking oxygen from the air or water. Animals (as well as plants) produce carbon dioxide through respiration and the decomposition of their dead bodies. Most have no backbone (e.g. worms, snails, jellyfish, and insects). These are the invertebrates; some have exoskeletons (insects). Vertebrates have backbones, which support the body. Over 99% are smaller than humans. Animal cells do not have cell walls. Almost all animals, unlike most plants, possess a limited scheme of growth; that is, the adults of a given species are nearly identical in their characteristic form and are similar in maximum size. Most animals reproduce sexually, but some are capable of asexual reproduction under certain circumstances. Most animals have specialized means of locomotion, generally involving muscle cells, and possess nervous systems and sense organs - all adaptations for securing food. Habitats include forests, plains, mountains, rivers, seas, and caves. Animal ClassificationThe main classification of animals however, relies not on how they eat, but on other characteristics:
Amphibians (e.g. frogs, newts, salamanders)Amphibians hatch from eggs as tadpoles and live both in and out of water. They usually stay near water, and have soft, moist skin. Amphibians are a class of tetrapod vertebrates, which are a link between fishes and the true land-living vertebrates like reptiles, birds and mammals.
BirdsBirds lay eggs, and have feathers. They are descended from dinosaurs. Birds (Class Aves) are warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings. There are almost 9000 known species of birds in the world.
FishFish live under water, have gills for breathing, and lay many eggs. Fishes is the proper English plural form of "fish" that biologists use when speaking about two of more fish species. There are over 25,000 fishes in the world (meaning that there are over 25,000 fish species in the world). When speaking of many fish that all are part of the same species, then the word "fish" is used. There are several million fish in the species Gadus morhua.
Mammals (e.g. Dolphins, Elephants, Horses, Pandas)Mammals are warm-blooded; the young are born alive (i.e. not from eggs, except for the duck-billed platypus and the echidna). They feed on mother's milk. They have fur or hair or quills. The mammals (scientific name Mammalia) are the class of animals primarily characterized by the presence of mammary glands in the female which produce milk for the nourishment of young, the presence of hair or fur, and have endothermic or "warm blooded" bodies.
Reptiles (e.g. alligators, snakes)Reptiles spend most of their time on land and lay soft-shelled eggs. The young look like small adults. Animal Posters
More Animal PostersSee also: Nature, Animals Posters
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
EncycloZine ® © 1998 - 2006 • Artzia.com • CuriousMinds.co.UK • diXionary.com • Eluzions.com • Kosmoi.com |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
