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The cell is the fundamental unit of structure and function in all living organisms. [14] The activity of an organism depends on the total activity of independent cells. [15] Energy flow (metabolism and biochemistry) occurs within cells. Cells contain DNA which is found specifically in the chromosome and RNA found in the cell nucleus and ...
The eukaryotic cell seems to have evolved from a symbiotic community of prokaryotic cells. DNA-bearing organelles like mitochondria and chloroplasts are remnants of ancient symbiotic oxygen-breathing bacteria and cyanobacteria, respectively, where at least part of the rest of the cell may have been derived from an ancestral archaean prokaryote ...
The following dates are approximations. 700 BC: Pythagoras's theorem is discovered by Baudhayana in the Hindu Shulba Sutras in Upanishadic India. [18] However, Indian mathematics, especially North Indian mathematics, generally did not have a tradition of communicating proofs, and it is not fully certain that Baudhayana or Apastamba knew of a proof.
In this view, the cell was seen to be enclosed by a thin surface, the plasma membrane, and cell water and solutes such as a potassium ion existed in a physical state like that of a dilute solution. In 1889, Hamburger used hemolysis of erythrocytes to determine the permeability of various solutes. By measuring the time required for the cells to ...
1858 – Rudolf Virchow proposed that cells can only arise from pre-existing cells; "Omnis cellula e celulla," all cell from cells. The Cell Theory states that all organisms are composed of cells (Schleiden and Schwann), and cells can only come from other cells (Virchow). 1864 – Louis Pasteur disproved the spontaneous generation of cellular life.
A team of scientists reports a new form of biological reproduction in the, <1 mm sized, xenobots that are made up of and are emersed in frog cells. [173] [174] A method of DNA data storage with 100 times the density of previous techniques is announced. [175] A stem cell-based treatment for Type 1 diabetes is announced. [176] [177]
1992 – Discovery of transitional B cells (David Allman & Michael Cancro) [16] [17] 1994 – Danger model of immunological tolerance is described by Polly Matzinger at the NIH 1995 – James P. Allison is the first to describe the function of the critical immune checkpoint CTLA-4
The Hooke Medal is an annual award by the British Society for Cell Biology, to recognise "an emerging leader in cell biology". [183] List of new memorials to Robert Hooke 2005–2009 erected the occasion of the tercentenary of his death; The Boyle-Hooke plaque in Oxford