a normal, genetically regulated process leading to the death of cells and triggered by the presence or absence of certain stimuli, as DNA damage.
(biology) the programmed death of some of an organism’s cells as part of its natural growth and development Also called programmed cell death
A natural process of self-destruction in certain cells, such as epithelial cells and erythrocytes, that are genetically programmed to have a limited life span or are damaged. Apoptosis can be induced either by a stimulus, such as irradiation or toxic drugs, or by removal of a repressor agent. The cells disintegrate into membrane-bound particles that are then eliminated by phagocytosis. Also called programmed cell death.
The programmed death of a cell. Scientists believe that this process is governed by chemical signals a given cell receives from its neighbors.
Note: It is thought some forms of cancer may result when this process of cell death is somehow interrupted, allowing cells to grow unchecked, with the result being a cancerous tumor.
(in sponges) a pore in each of the saclike chambers formed by the evagination of the body wall, through which water passes into the excurrent canals.
aporepressor aporepressor ap·o·re·pres·sor (āp’ə-rĭ-prěs’ər) n. A repressor that combines with a specific corepressor to inhibit transcription of certain genes; it is a homeostatic mechanism for the regulation of repressible enzyme systems. Also called inactive repressor.
adjective tending to doubt Examples The aporetic voice is that which expresses wonder and perplexity. Word Origin from a Greek word meaning ‘to be at a loss’ adj. c.1600, from French aporetique, from Greek aporetikos, from aporeein “to be at a loss,” from aporos “impassable, impracticable, very difficult; hard to deal with; at a loss,” […]
Rhetoric. the expression of a simulated or real doubt, as about where to begin or what to do or say. Logic, Philosophy. a difficulty encountered in establishing the theoretical truth of a proposition, created by the presence of evidence both for and against it. Contemporary Examples Often Socratic conversation induces utter confusion—the ancient Greek word […]