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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 ...
The three-domain system adds a level of classification (the domains) "above" the kingdoms present in the previously used five- or six-kingdom systems.This classification system recognizes the fundamental divide between the two prokaryotic groups, insofar as Archaea appear to be more closely related to eukaryotes than they are to other prokaryotes – bacteria-like organisms with no cell nucleus.
In cell biology, an organelle is a specialized subunit, usually within a cell, that has a specific function.The name organelle comes from the idea that these structures are parts of cells, as organs are to the body, hence organelle, the suffix -elle being a diminutive.
Robert Remak (26 July 1815 – 29 August 1865) was an embryologist, physiologist and neurologist, born in Posen, Prussia, who discovered that the origin of cells was by the division of pre-existing cells.
It can be virtual (part of a flashcard software) or physical. Typically, each flashcard bears a question or definition on one side and an answer or target term on the other. As such, flashcards are often used to memorize vocabulary, historical dates, formulae, or any subject matter that can be learned via a question-and-answer format.
In 1903, Nikolai K. Koltsov proposed that the shape of cells was determined by a network of tubules that he termed the cytoskeleton. The concept of a protein mosaic that dynamically coordinated cytoplasmic biochemistry was proposed by Rudolph Peters in 1929 [12] while the term (cytosquelette, in French) was first introduced by French embryologist Paul Wintrebert in 1931.
A cell's ability to vitrify in the absence of metabolic activity, as in dormant periods, may be beneficial as a defense strategy. A solid glass cytoplasm would freeze subcellular structures in place, preventing damage, while allowing the transmission of tiny proteins and metabolites, helping to kickstart growth upon the cell's revival from ...
Protoplasm (/ ˈ p r oʊ t ə ˌ p l æ z əm /; [1] [2] pl. protoplasms) [3] is the part of a cell that is surrounded by a plasma membrane.It is a mixture of small molecules such as ions, monosaccharides, amino acids, and macromolecules such as proteins, polysaccharides, lipids, etc.