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  2. Cell theory - Wikipedia

    en.wikipedia.org/wiki/Cell_theory

    From these conclusions about plants and animals, two of the three tenets of cell theory were postulated. 1. All living organisms are composed of one or more cells 2. The cell is the most basic unit of life. Schleiden's theory of free cell formation through crystallization was refuted in the 1850s by Robert Remak, Rudolf Virchow, and Albert ...

  3. Logical quality - Wikipedia

    en.wikipedia.org/wiki/Logical_quality

    Logical quality has become much less central to logical theory in the twentieth century. It has become common to use only one logical quality, typically called logical assertion . Much of the work previously done by distinguishing affirmation from denial is typically now done through the theory of negation . [ 2 ]

  4. Hayflick limit - Wikipedia

    en.wikipedia.org/wiki/Hayflick_limit

    The typical normal human fetal cell will divide between 50 and 70 times before experiencing senescence. As the cell divides, the telomeres on the ends of chromosomes shorten. The Hayflick limit is the limit on cell replication imposed by the shortening of telomeres with each division. This end stage is known as cellular senescence.

  5. Programmed cell death - Wikipedia

    en.wikipedia.org/wiki/Programmed_cell_death

    Programmed cell death (PCD; sometimes referred to as cellular suicide [1]) is the death of a cell as a result of events inside of a cell, such as apoptosis or autophagy. [ 2 ] [ 3 ] PCD is carried out in a biological process , which usually confers advantage during an organism's lifecycle .

  6. Outline of cell biology - Wikipedia

    en.wikipedia.org/wiki/Outline_of_cell_biology

    Light micrograph of a moss's leaf cells at 400X magnification. The following outline is provided as an overview of and topical guide to cell biology: . Cell biology – A branch of biology that includes study of cells regarding their physiological properties, structure, and function; the organelles they contain; interactions with their environment; and their life cycle, division, and death.

  7. Affirmation and negation - Wikipedia

    en.wikipedia.org/wiki/Affirmation_and_negation

    Affirmation and negation are a crucial building blocks for language. The presence of negation is the absence of affirmation, where affirmation functions individually. [1] There are three main aspects to the concept of affirmation and negation; Cognitive, psychological and philosophical (Schopenhauers theory or Nietzschean affirmation).

  8. Cellular senescence - Wikipedia

    en.wikipedia.org/wiki/Cellular_senescence

    Cells can also be induced to senesce by DNA damage in response to elevated reactive oxygen species (ROS), activation of oncogenes, and cell-cell fusion. Normally, cell senescence is reached through a combination of a variety of factors (i.e., both telomere shortening and oxidative stress). [13]

  9. Cataphatic theology - Wikipedia

    en.wikipedia.org/wiki/Cataphatic_theology

    Saint Dionysus taught the apophatic way, which involves stripping away any conceptual understanding of God that might become all-encompassing. This approach prevents the limited nature of human understanding from imposing itself on the absolute and divine. [5]