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Carolus Linneaus
Carolus Linnaeus is one of the giants of natural science. He devised the formal two-part naming system we use to classify all lifeforms. A well-known example of his two-part system is the dinosaur Tyrannosaurus rex; another is our own species – Homo sapiens. Linnaeus pushed the science of biology to new heights by describing and classifying our own human species in precisely the same way as he classified other lifeforms. Other people at that time demanded that humans must be regarded -
Lamarck
He was the first to propose a mechanism by which the gradual change of species might take place. Also, he extended the definition of the change over time, saying that life started out simple and became more complex. The second part of Lamarck's mechanism for evolution involved the inheritance of acquired traits. He believed that traits changed or acquired over an individual's lifetime could be passed down to its offspring. -
Hutton
His most important contribution to science was his Theory of the Earth, (1785). For this theory Hutton has earned the accolade of 'founder of modern geology'. Hutton's theory put forward the idea that fusion of sediments arose by the great heat which he believed to exist beneath the lower regions of the earth's crust. Heat, he claimed, was capable of fusing all the substances found in different types of sediment. -
Cuvier
uvier established extinctions as a fact that any future scientific theory of life had to explain. In Darwin's theory, species that did not adapt to changing environments or withstand the competition of other species faced annihilation. Darwin did not, however, accept all of Cuvier's ideas on extinctions. Like Charles Lyell before him, he doubted that species went extinct in great "catastrophes." -
Lyell
Principles of Geology, Lyell's first book,it established Lyell's credentials as an important geological theorist and propounded the doctrine of uniformitarianism. -
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Genetics and DNA contributions
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Gregor Mendel
Known as the father of genetics, began his study of inherintence in 1854.
mendel's 3 laws:
law of dominance (dominant and recessive inheritance)
law of segregation (how the genes (chromosomes) divide up during meiosis)
law of independent assortment (crossing over) -
Darwin
Darwin published his theory of evolution with compelling evidence in his book On the Origin of Species. Darwins theory established that all species of life descended over from common ancestors. His scientific theory that this branching pattern of evolution resulted from a process that he called natural selection. -
stem cells
an undifferentiated cell of a multicellular organism that is capable of giving rise to indefinitely more cells of the same type, and from which certain other kinds of cell arise by differentiation. -
pharmaceuticals
This is a compound manufactured for use as a medicinal drug.
companies manufacturing medicinal drugs. -
Avery-Macleod-Mcarty experiement
Extracted components from heat-killed S bacteria.
After each extraction, S cells were mixed with R bacteria.
R bacteria transformed each time until DNA was extracted from S cells.
Avery and his colleagues concluded that DNA was the "transforming principle." -
Maurice WIlkins
Wilkins studied biological molecules like DNA and viruses using a variety of microscopes and spectrophotometers. He eventually began using X-rays to produce diffraction images of DNA molecules. The X-ray diffraction images produced by him, Rosalind Franklin, and Raymond Gosling led to the deduction by James Watson and Francis Crick of the 3-dimensional helical nature of DNA. -
Rosalind Franklin
She had been asked to set up a laboratory to study DNA fibres using X-ray crystallography, where atoms can be precisely mapped by looking at the image of the crystal under an X-ray beam. She had the entire responsibility for determining the structure of DNA. Franklin was able to apply her knowledge of physical chemistry and as a result, she made thinner fibers in order to produce more exact and easier to interpret X-ray patterns. -
Hershey-chase
Hershey and Chase radioactively labelled T2 bacteriophage with P (DNA) and S (protein) to determine if protein or DNA carried the genetic material. They let the bacteriophage infect E.coli. The radioactive material found in the host E.coli contained the radioactive P (found in DNA) as the bacteriophage had multiplied inside the cell, but the radioactive S was not found inside the cell. Therefore DNA is the hereditary molecule -
Cloning aninmals
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Watson and Crick
They began building three-dimensional models, using cardboard cutouts and sheet metal to represent the molecule's chainlike structure. They were aware that DNA might have the general, winding shape of a helix. But how DNA's four bases were arranged around a sugar and phosphate backbone remained a mystery. They determined the structure of DNA, it is a double helix -
gel electrophoresis
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restriction enzyme analysis
Special enzymes termed restriction enzymes have been discovered in many different bacteria and other single-celled organisms. These restriction enzymes are able to scan along a length of DNA looking for a particular sequence of bases that they recognize. This recognition site or sequence is generally from 4 to 6 base pairs in length. Once it is located, the enzyme will attach to the DNA molecule and cut each strand of the double helix. The restriction enzyme will continue to do this along the fu -
plasmid based transformation
Transformation is the process by which foreign DNA is introduced into a cell. Transformation of bacteria with plasmids is important not only for studies in bacteria but also because bacteria are used as the means for both storing and replicating plasmids. Because of this, nearly all plasmids, even those designed for use in mammalian cells, carry both a bacterial origin of replication and an antibiotic resistance gene for use as a selectable marker in bacteria. -
genetic engineering
Genetic engineering is the process of manually adding new DNA to an organism. The goal is to add one or more new traits that are not already found in that organism. -
polymerase chain reaction (PCR)
The polymerase chain reaction is a technology in molecular biology used to amplify a single copy or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence. -
transgenic animals
A transgenic animal is one that carries a foreign gene that has been deliberately inserted into its genome. The foreign gene is constructed using recombinant DNA methodology. In addition to the gene itself, the DNA usually includes other sequences to enable it
to be incorporated into the DNA of the host and
to be expressed correctly by the cells of the host.
Transgenic sheep and goats have been produced that express foreign proteins in their milk.
Transgenic chickens are now able to synthesize h -
GMOs
A genetically modified organism (GMO) is any organism whose genetic material has been altered using genetic engineering techniques. GMOs are the source of genetically modified foods and are also widely used in scientific research and to produce goods other than food. -
human genome project (HGP)
The Human Genome Project is an international scientific research project with the goal of determining the sequence of chemical base pairs which make up human DNA, and of identifying and mapping all of the genes of the human genome from both a physical and functional standpoint.
