| APHIS | Animal and Plant Health Inspection Service |
|---|---|
| PTSM | Plant, Technology and Safety Management |
| NCPPB | National Collection of Plant Pathogenic Bacteria |
| PGS | peristent gross splenomegaly; Pettigrew syndrome; plant growth substance; postsurgical gastroparesis... |
| PPT | parietal pleural tissue; partial prothrombin time; peak-to-peak threshold; Pfeiffer-Palm-Teller [syn... |
D factor
| divergent evolution | The process by which a species or gene product gives rise to two or more different products. (05 Mar 2000) |
|---|---|
| Douglas' spontaneous evolution | A mechanism whereby molding of the foetus and impaction of the shoulder and prolapsed arm occurs in transverse lie, allowing vaginal delivery with the lateral aspect of the thorax following the prolapsed shoulder. (05 Mar 2000) |
| quantum evolution | An extremely rapid evolutionarychange in a single genetic lineage, thought to result from a sudden and radical change in the species'environment. (09 Oct 1997) |
| organic evolution | Biologic evolution was contrasted with cultural evolution in 1968 by A.G. Motulsky who pointed out that biologic evolution is mediated by genes, shows a slow rate of change, employs random variation (mutations) and selection as agents of change, new variants are often harmful, these new variants are transmitted from parents to offspring, the mode of transmission is simple, complexity is achieved by the rare formation of new genes by chromosome duplication, biologic evolution occurs with all forms of life, and the biology of humans requires cultural evolution. See Cultural evolution. (12 Dec 1998) |
| emergent evolution | Appearance of a property in a complex system e.g., organism that could have been predicted only with difficulty, or perhaps not at all, from a knowledge and understanding of the individual genotype changes taken separately. (05 Mar 2000) |
| evolution | 1. An unrolling. 2. A process of development in which an organ or organism becomes more and more complex by the differentiation of its parts, a continuous and progressive change according to certain laws and by means of resident forces. Origin: L. Evolutio (18 Nov 1997) |
| evolution, biologic | A.G. Motulsky in 1968 contrasted biologic evolution with cultural evolution, pointing out that biologic evolution is mediated by genes, shows a slow rate of change, employs random variation (mutations) and selection as agents of change, new variants are often harmful, these new variants are transmitted from parents to offspring, the mode of transmission is simple, complexity is achieved by the rare formation of new genes by chromosome duplication, biologic evolution occurs with all forms of life, and the biology of humans requires cultural evolution. See Evolution, cultural. (12 Dec 1998) |
| evolution, chemical | Chemical and physical transformation of the biogenic elements from their nucleosynthesis in stars to their incorporation and subsequent modification in planetary bodies and terrestrial biochemistry. It includes the mechanism of incorporation of biogenic elements into complex molecules and molecular systems, leading up to the origin of life. (12 Dec 1998) |
| evolution, cultural | By contrast with biologic evolution, A.G. Motulsky in 1968 pointed out that social evolution is mediated by ideas, shows a rapid (exponential) rate of change, is usually purposeful, often beneficial, is widely disseminated by diverse means, is frequently transmitted in complex ways, further complexity comes from the frequent formation of new ideas and new technologies. Cultural evolution is unique to humans among all forms of life. Human culture required biologic evolution to achieve the human brain. See Evolution, social. (12 Dec 1998) |
| evolution, molecular | Evolution at the molecular level of DNA sequences and proteins. (rieger et al., glossary of genetics: classical and molecular, 5th ed) (12 Dec 1998) |
| evolution, planetary | Creation and development of bodies within solar systems, includes study of early planetary geology. (12 Dec 1998) |
| air plant | <botany> A plant deriving its sustenance from the air alone; an aerophyte. The "Florida moss" (Tillandsia), many tropical orchids, and most mosses and lichens are air plants. Those which are lodged upon trees, but not parasitic on them, are epiphytes. Source: Websters Dictionary (01 Mar 1998) |
| aquatic plant | <botany> Plants that must grow in water whether rooted in the mud or floating without anchorage, plants that must complete part or all of their life cycle in or near the water. (09 Oct 1997) |
| C3 plant | <plant biology> Plants that fix carbon dioxide in photosynthesis by the Calvin Benson cycle. The enzyme responsible for carbon dioxide fixation is RuDP carboxylase, whose products are compounds containing three carbon atoms. C3 plants are typical of temperate climates. Photorespiration in these plants is high. (07 Nov 1997) |
| C4 plant | <plant biology> Plants found principally in hot climates whose initial fixation of carbon dioxide in photosynthesis is by the HSK pathway. The enzyme responsible is PEP carboxylase, whose products contain four carbon atoms. Subsequently the carbon dioxide is released and re fixed by the Calvin Benson cycle. The presence of the HSK pathway permits efficient photosynthesis at high light intensities and low carbon dioxide concentrations. most species of this type have little or no photorespiration. (21 Mar 1998) |