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Biology. Johannes Friedrich Miescher (13 August 1844 – 26 August 1895) was a Swiss physician and biologist. He was the first scientist to isolate nucleic acid in 1869. Miescher also identified protamine and made several other discoveries. Miescher had isolated various phosphate-rich chemicals, which he called nuclein (now nucleic acids), from ...
Deoxyribozymes, also called DNAzymes or catalytic DNA, were first discovered in 1994. [170] They are mostly single stranded DNA sequences isolated from a large pool of random DNA sequences through a combinatorial approach called in vitro selection or systematic evolution of ligands by exponential enrichment (SELEX).
Phylogenetic tree linking all major groups of living organisms, namely the Bacteria, Archaea, and Eukarya, as proposed by Woese et al 1990, [ 1 ] with the last universal common ancestor (LUCA) shown at the root. The last universal common ancestor (LUCA) is the hypothesized common ancestral cell from which the three domains of life, the Bacteria ...
1944: The Avery–MacLeod–McCarty experimentisolates DNAas the genetic material (at that time called transforming principle). [24] 1947: Salvador Luriadiscovers reactivation of irradiated phage,[25]stimulating numerous further studies of DNA repair processes in bacteriophage,[26]and other organisms, including humans.
The history of genetics dates from the classical era with contributions by Pythagoras, Hippocrates, Aristotle, Epicurus, and others. Modern genetics began with the work of the Augustinian friar Gregor Johann Mendel. His works on pea plants, published in 1866, provided the initial evidence that, on its rediscovery in 1900's, helped to establish ...
One of the strongest evidences for common descent comes from gene sequences. Comparative sequence analysis examines the relationship between the DNA sequences of different species, [ 1 ] producing several lines of evidence that confirm Darwin's original hypothesis of common descent. If the hypothesis of common descent is true, then species that ...
Hershey–Chase experiment. The Hershey–Chase experiments were a series of experiments conducted in 1952 [1] by Alfred Hershey and Martha Chase that helped to confirm that DNA is genetic material. While DNA had been known to biologists since 1869, [2] many scientists still assumed at the time that proteins carried the information for ...
Evolution is the change in the heritable characteristics of biological populations over successive generations. [1] [2] It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. [3]