meiosis

meiosis
The process of division of sex cells, resulting in the formation of gametes (eggs or sperm cells). In meiosis the nucleus undergoes two separate divisions, but the chromosomes are duplicated only once. So the four daughter cells each possess only half the chromosomes of the parent cell. When the egg and sperm, each with half a complement of chromosomes, unite, the two halves join together, resulting in a fertilized egg with the full number of chromosomes. This is a principal source of the difference between offspring and parents. During meiosis the original chromosomes may break and rejoin with others lying alongside them; this process (crossing over) is also a source of genetic variation. In philosophical discussion of abortion, it is sometimes suggested that it is only after the joining up process that we have a single entity with the potential for life, and that this separates the morality of abortion from that of birth control.

Philosophy dictionary. . 2011.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • Meiosis — es una de las formas de la reproducción celular. Este proceso se realiza en las glandulas sexuales para la produccion de gametos. Es un proceso de división celular en el cual una célula diploide (2n) experimenta dos divisiones sucesivas, con la… …   Wikipedia Español

  • meiosis — f. citol. División celular propia de las células germinales durante el proceso de maduración que transformará la ovogonia en ovocito y la espermatogonia en espermatocito. Se trata de una división reduccional, es decir, una división celular en la… …   Diccionario médico

  • meiosis — division of a cell nucleus, 1905, from Gk. meiosis a lessening, from meioun to lessen, from meion less, from PIE root *mei small (see MINUS (Cf. minus)). Earlier (1580s) it was a rhetorical term, a figure of speech weak or negative expression… …   Etymology dictionary

  • meiosis — pronounced miy oh sis, is a figure of speech involving an emphatic understatement made for effect, as when something outstanding is described as ‘rather good’. A literary example occurs in Shakespeare s Romeo and Juliet, where Mercutio refers to… …   Modern English usage

  • meiosis — o meyosis sustantivo femenino 1. Área: biología Proceso de división celular por el cual, a partir de una célula madre, se originan cuatro células hijas o gametos y se reduce el número de cromosomas a la mitad: La meiosis está presente en el… …   Diccionario Salamanca de la Lengua Española

  • meiosis — [mī ō′sis] n. [ModL < Gr meiōsis < meioun, to make smaller < meiōn, less: see MINOR] 1. the process of two consecutive nuclear divisions in the formation of germ cells in animals and of spores in most plants, by which the number of… …   English World dictionary

  • Meiosis — Mei*o sis (m[ i]*[=o] s[i^]s), n. [NL., fr. Gr. mei wsis, fr. meioy^n to make smaller, from mei wn. See {Meionite}.] 1. (Rhet.) Diminution; a species of hyperbole, representing a thing as being less than it really is; understatement; see also… …   The Collaborative International Dictionary of English

  • meiosis — meiosis. См. деление созревания. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Meiōsis — (gr.), 1) krankhafte Verkleinerung eines Theils; 2) so v.w. Myosis; 3) rhetorische Figur, die, scheinbar verkleinernd, vergrößert; z.B. Abraham war nicht schwach (d.i. sehr stark) im Glauben …   Pierer's Universal-Lexikon

  • Meiosis — Meiosis, griech. = Verminderung, rhetorische Figur, wobei man sich eines scheinbar verringernden Ausdrucks bedient, um den Gegenstand schärfer hervorzuheben …   Herders Conversations-Lexikon

  • meiosis — (Del gr. μείωσις, disminución). f. Biol. Sucesión de dos divisiones celulares durante la formación de los gametos, de la que resultan cuatro células que tienen un cromosoma de cada pareja de la célula original …   Diccionario de la lengua española

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”