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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 ...
In comparison to the original theory, bioecological systems theory adds more emphasis to the person in the context of development. Additionally, Bronfenbrenner chose to leave out key features of the ecological systems theory (e.g., ecological validity and ecological experiments) during his development of bioecological systems theory. As a whole ...
During embryonic development, cells are restricted to different layers due to differential affinities. One of the ways this can occur is when cells share the same cell-to-cell adhesion molecules. For instance, homotypic cell adhesion can maintain boundaries between groups of cells that have different adhesion molecules.
Hebbian theory is a neuropsychological theory claiming that an increase in synaptic efficacy arises from a presynaptic cell's repeated and persistent stimulation of a postsynaptic cell. It is an attempt to explain synaptic plasticity , the adaptation of brain neurons during the learning process.
According to Otto Kandler's pre-cell theory, [1] [2] [3] early evolution of life and primordial metabolism (see Iron-Sulfur world hypothesis - metabolism first scenario, according to Wächtershäuser [5] [6]) led to the early diversification of life through the evolution of a multiphenotypical population of pre-cells, [1] [2] [3] from which the three founder groups A, B, C and then, from them ...
Naturalists of the late 18th century and the 19th century embraced Wolff's philosophy, but primarily because they rejected the application of mechanistic development, as seen in the expansion of miniature organisms. It was not until the late 19th century that preformationism was discarded in the face of cell theory. Now, scientists "realized ...
English: Kandler's pre-cell theory (Kandler 1998, Figure 2.3, p.22) - Scheme of cellularisation (modified after Kandler 1994, p.155)ː Scenario of the early evolution and diversification of life through the development of a multiphenotypical population of pre-cells from which the founder groups (A, B, C) and then, from them, the precursor cells (proto-cells) of the three domains of life (Woese ...
In 1759 he graduated as an M.D. from the University of Halle with his dissertation "Theoria Generationis", where he revived and supported the theory of epigenesis previously proposed by Aristotle and William Harvey. The paper consisted of three parts devoted to (1) development of plants, (2) development of animals, and (3) theoretical ...