Reproduced courtesy of David Spears © Clouds Hill Imaging Ltd. DEFINITION:1 any of an order (Siphonaptera) of small, flattened, wingless insects with large legs adapted for jumping: as adults they are bloodsucking parasites on mammals and birds. The flea is one of the most troublesome of insects and one of the most dangerous. Rat fleas [...]

A deliberate self-denial of food and drink, usually for religious or ethical reasons, is called fasting. The word is probably derived from a Teutonic or Germanic term meaning “to be strict” or “to observe.” In addition to fasting, many religions also have dietary restrictions: certain foods are not to be eaten by believers of a [...]

DEFINITION: the branch of biology dealing with the splicing, and recombining, of specific genetic units from the DNA of living organisms: it is used to modify the existing genetic codes to produce new, or improved, species, valuable biochemicals. 1865: The birth of genetics. It was unfortunate for the biological sciences that Gregor Mendel was an [...]

Genetic engineering had its origins during the late 1960s and early 1970s in experiments with bacteria, viruses, and small, free-floating rings of deoxyribonucleic acid (DNA) called plasmids, found in bacteria. While investigating how these viruses and plasmids move from cell to cell, recombine, and reproduce themselves, scientists discovered that bacteria make enzymes, called restriction enzymes, [...]

DEFINITIONS: CRICKET – 1 any of various families (esp. Gryllidae) of generally dark-coloured, leaping, orthopteran insects usually having long antennae: the males produce a characteristic chirping noise by rubbing parts of the fore wings together 2 a small metal toy or signalling device that makes a clicking sound when pressed. GRASSHOPPER – 1 any of [...]

DEFINITION:1 a) the branch of biology that deals with the relations between living organisms and their environment b) the complex of relations between a specific organism and its environment 2 Sociology the study of the relationship and adjustment of human groups to their geographical and social environments. 1869: Birth of ecology. Most people are unaware [...]

Competition in Communities Competition is a characteristic of all communities. Plant roots in dry range lands compete for water. The trees of a rain forest compete for light. Crops compete for both of these as well as for nutrients. Competition is usually keen in areas where one type of community seems to overlap another. For [...]

HOW DDT KILLED THE ROBINS. Dutch elm disease threatened to destroy most of the majestic elms that once flourished along residential streets. To eliminate the beetles that carry this fungus disease, many communities sprayed their elms with massive doses of DDT. The pesticide stuck to the leaves even after they fell in the autumn. Earthworms [...]

  DEFINITION: any of a large super family (Apoidea) of broad-bodied, four-winged, hairy hymenopteran insects that gather pollen and nectar, have biting as well as sucking mouth parts, and often live in organized colonies; esp., the honeybee. People have known ever since ancient times that the insects called bees make delicious honey from the nectar [...]

Nesting and Life Cycle Social insects, those living in communities and having differentiated forms or castes, as queens, workers, drones. Bees vary greatly in nesting practices, depending upon the species. They may be classified as social bees, solitary bees, and parasitic bees (also called guest bees or cuckoo bees). Social bees are members of colonies [...]