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  2. Land degradation - Wikipedia

    en.wikipedia.org/wiki/Land_degradation

    Overgrazing by livestock can lead to land degradation. Land degradation is a process where land becomes less healthy and productive due to a combination of human activities or natural conditions. The causes for land degradation are numerous and complex. [1] Human activities are often the main cause, such as unsustainable land management practices.

  3. DNA laddering - Wikipedia

    en.wikipedia.org/wiki/DNA_laddering

    DNA laddering (left) visualised in an agarose gel by ethidium bromide staining. A 1 kb marker (middle) and control DNA (right) are included.. DNA laddering is a feature that can be observed when DNA fragments, resulting from Apoptosis DNA fragmentation are visualized after separation by gel electrophoresis the first described in 1980 by Andrew Wyllie at the University Edinburgh medical school ...

  4. DNA - Wikipedia

    en.wikipedia.org/wiki/DNA

    DNA is a long polymer made from repeating units called nucleotides. [6] [7] The structure of DNA is dynamic along its length, being capable of coiling into tight loops and other shapes. [8] In all species it is composed of two helical chains, bound to each other by hydrogen bonds.

  5. Apoptotic DNA fragmentation - Wikipedia

    en.wikipedia.org/wiki/Apoptotic_DNA_fragmentation

    In 1974, Williams, Little, and Shipley, using cells exposed to widely differing types of trauma, found that during cell death, degraded DNA in "every case had a modal value of between 10(x6) and 10(x7) Dalton and cellular metabolism is required to produce degradation of DNA".

  6. Environmental DNA - Wikipedia

    en.wikipedia.org/wiki/Environmental_DNA

    The longhorn beetle, Leptura quadrifasciata, is an example of a flower‐visiting insect found in a study which showed that environmental DNA (eDNA) from arthropods is deposited on wild flowers after interactions [1]

  7. Nucleic acid double helix - Wikipedia

    en.wikipedia.org/wiki/Nucleic_acid_double_helix

    The double-helix model of DNA structure was first published in the journal Nature by James Watson and Francis Crick in 1953, [6] (X,Y,Z coordinates in 1954 [7]) based on the work of Rosalind Franklin and her student Raymond Gosling, who took the crucial X-ray diffraction image of DNA labeled as "Photo 51", [8] [9] and Maurice Wilkins, Alexander Stokes, and Herbert Wilson, [10] and base-pairing ...

  8. Genetic erosion - Wikipedia

    en.wikipedia.org/wiki/Genetic_erosion

    The major driving forces behind genetic erosion in crops are variety replacement, land clearing, overexploitation of species, population pressure, environmental degradation, overgrazing, governmental policy, and changing agricultural systems. The main factor, however, is the replacement of local varieties of domestic plants and animals by other ...

  9. DNA fragmentation - Wikipedia

    en.wikipedia.org/wiki/DNA_fragmentation

    Apoptotic DNA fragmentation is a natural fragmentation that cells perform in apoptosis (programmed cell death). DNA fragmentation is a biochemical hallmark of apoptosis.In dying cells, DNA is cleaved by an endonuclease that fragments the chromatin into nucleosomal units, which are multiples of about 180-bp oligomers and appear as a DNA ladder when run on an agarose gel. [8]