|
Search over 100 encyclopedias and dictionaries: |
Research categories | Follow us on Twitter |
Research categories
View all topics in the newsView all reference sources at Encyclopedia.com |
|||
|
biotic potential
biotic potential (intrinsic rate of increase) Symbol r. The number of offspring of an individual organism that would survive to reproductive age under ideal conditons. It is a measure of an individual's reproductive potential, although this is seldom fully realized under natural conditons. Organisms... Read more |
|
reproductive isolating mechanism
reproductive isolating mechanism (RIM) The means by which different species are kept reproductively isolated. These may be: (a) chromosomal (if cross-mating occurs, the incompatibility of the karyotypes makes any hybrid inviable or sterile); (b) mechanical (the two species cannot mate because they... Read more |
|
proglottis
proglottis (pl. proglottides) In Cestoda, one of the segments of which the animal consists. Each proglottis is essentially a reproductive sac with both male and female organs. The posterior segments, containing fertilized eggs, break off and are passed out with the host's faeces. Proglottides are... Read more |
|
|
antique
antique The term has been used collectively to designate classical Greek and Roman works of art, particularly sculptures; as an adjective to indicate an object, a period, or a style of ancient or early times; and as a noun, for objects of art, furniture, rugs, pottery, metalwork, costumes,... Read more |
|
ageing
ageing Why ageing occursAgeing affects all parts of the body and leads to increasing frailty, a declining capacity to respond to stress, increasing incidence of age-related diseases, and eventually, death. Why the body should undergo this spectrum of degenerative changes, when it is equipped with... Read more |
|
biological species concept
biological species concept (BSC) The concept of a species as a group of populations whose members are capable of interbreeding successfully and are reproductively isolated from other groups. This concept became influential during the late 19th and early 20th centuries, largely replacing the... Read more |
|
|
sculpture
sculpture art of producing in three dimensions representations of natural or imagined forms. It includes sculpture in the round, which can be viewed from any direction, as well as incised relief , in which the lines are cut into a flat surface. See also articles on special techniques, e.g., ... Read more |
|
Buster Keaton
Buster Keaton (Joseph Francis Keaton), 1895-1966, American movie actor, b. Piqua, Kans. Considered one of the greatest comic actors in film history, Keaton used his considerable acrobatic skills, which he had developed as a child in vaudeville, in many silent comedies in which he portrayed a... Read more |
|
|
puberty
puberty , period during which the onset of sexual maturity occurs. It usually takes place between the ages of 10 and 15 in both sexes but sometimes occurs as early as 7 or 8 years of age in females. The pituitary gland secretes hormones that stimulate enlargement and development of the sex organs,... Read more |
|
autotomy
autotomy The shedding by an animal of part of its body followed by the regeneration of the lost part. Autotomy is achieved by the contraction of muscles at specialized regions in the body. It serves as a protective mechanism if the animal is damaged or attacked (e.g. tail loss in certain reptiles)... Read more |
|
|
Hollywood Comedians, The Film Reader
...scholarly works for The Hollywood...the essay "Buster Keaton, or the work of Comedy in the Age of Mechanical Reproduction" Tom Gunning...grow, the comedy ... is...Comedian ... |