Dna And Forensics
.... Guanine (G), Adenine (A), Thymine (T), and Cytosine (C) are the four bases that make up the base pairs. The bases don't just pair with any other bases, there are certain predictable combinations: A with T and G with C, and these are true to any DNA. The human body contains in excess of three billion base pairs, only a few of these are what attract forensic attention. (Joe Mickel and John F. Fischer, 1998)
The first of the two procedures I will discuss is restriction fragment length polymorphism (R .....
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Dna Replication
.... there will be two new daughter strands synthesized. However, each of these daughter cells is synthesized in different ways.
The first strand of DNA is built by simply adding nucleotides to its end. This strand grows inward towards the replication fork as the DNA molecule unzips. This strand ends with a hydroxide (OH) group and is called the 3` prime or 3`end. The enzyme that catalyzes this process is called DNA polymerase.
The second strand is built by having a polymerase jump ahead on the strand .....
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Down Syndrome 2
.... chromosomes is 46, however the
excess material from the twenty-first chromosome results in the
affects of the syndrome. With translocation, most cases occur
sporadically, with no bearing on maternal age. These two types
of this syndrome are very rare, being responsible for only 6 or
7 percent of all cases.
Children with Down syndrome are at high risk for health
problems. These include congenital heart defects, respiratory
problems, increased suseptibility to infections, and/or
obstruct .....
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Down Syndrome 3
.... muscle tone
· Flat facial profile
· Upward slant to the eyes
· Abnormal shape and small size of the ears
· Single deep crease across the center of the palm
· Excessive ability to extend the joints
· Fifth finger has one bending joint instead of two
· Small skin folds on the inner corners of the eyes
· Excessive space between large and second toe
· Enlargement of tongue in relationship to size of mouth
The majority of these defects can be corrected, resulting in long-term health improve .....
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Down Syndrome 4
.... the
1970s, an American revision of scientific terms changed it simply to "Down
syndrome," while it still is called "Down's" in Europe.
In the first part of the twentieth century, there was much speculation of
the cause of Down syndrome. The first people to speculate that it might be
due to chromosomal abnormalities were Waardenberg and Bleyer in the
1930s. But it wasn't until 1959 that Jerome Lejeune and Patricia Jacobs,
working independently, first determined the cause to be trisomy of th .....
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Dreams Rem
.... the time when subjects were awakened during REM sleep, they reported a dream.
Prior to laboratory REM research, it was unknown how frequently Humans dreamed. Some theories even held that dreaming was a signal of mental disturbance. With laboratory REM research, however, subjects can be awakened after each REM period in order for researchers to extensively sample most mental activity that occurs during sleep. It was discovered that humans, and all mammals--except the echidna or spiny anteater, and pe .....
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Drinking Water Contamination
.... information about their drinking water supplies and the efficacy of their purifying methods. While the primary concern of most water utilities is delivering safe drinking water — and a large number readily share their water quality data with the public — many insist on erecting barriers between the public they serve and information about the water they supply.[6]
As a result of the failure of the government and many water systems in the country to protect the drinking water supply, many Americans no lon .....
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Droughts
.... wet low-pressure weather and a drought follows. A southward shift in the western winds causes the most severe drought of the 20th century, the one that struck the African region, Sahel for 12 years starting in 1968.
Statistics indicate that roughly every 22 years a major drought occurs in the United States, they affect the Prairie and midwestern states the most. The disastrous drought of 1933-35, during which large areas of the Great Plains became known as the Dust Bowl, is one example. The effe .....
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Drug Identification With Gas Chromatography Mass Spectrometr
.... positively charged ions now pass through the mass separator, which is a magnetic field. The mass separator isolates the fragmented sample into their masses. The isolated masses are read by an ion detector and then displayed as a mass chromatogram. A mass chromatograph is a graph of ion m/e abundance in relation to time. The gas chromatograph/mass spectrometer or GC/MS produces a mass chromatogram of a substance that acts like a fingerprint for a chemical substance.
The idea that a GC/MS produces a .....
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Dsl Should Be The Standard For Telephone Lines
.... DSL wouldn't only make our internet experience more enjoyable, but it would also improve the quality and reliability of normal phones. The digital format would be able to reproduce sound quality with great fidelity. Static-filled and "noisy" phone lines would be a thing of the past allowing for clearer long and short distance phone calls.
An upgrade to DSL would be a benefit to all. This amazing new technology would change both our internet browsing and phone experiences for the better.
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Dvd Vs. Vcr
.... are two main options of video components in a home entertainment system. The Video Cassette Recorder (VCR) and the Digital Video Disc (DVD) player are both positive additions to any home entertainment system. Both systems offer benefits and disadvantages to their users, and both should be carefully examined before a final decision is made on which one a consumer should purchase.The VCR was first developed in the 1950’s, but did not become a part of the average home entertainment system until the 1980’s, wh .....
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Dyslexia
.... can also be compared to amnesia because it is selective” (Bakker 23). Some experts use the term specific learning disability instead of dyslexia”
Despite much research, nobody knows what causes dyslexia. Current research is focused on such possible causes as genetics, physiology, biochemistry, and structural changes in the brain. “There are theories that something is wrong with the brain or that certain chemicals are missing. One of the most popular theory is that dyslexia is a structural defect in the .....
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Bacillus Anthracis
.... where workers must handle animal carcasses. The livestock version of the vaccine is very effective, however. The vaccine for both animals and humans is composed of sublethal amounts of toxin that induce formation of protective antibody. Frequent boosters are necessary to maintain resistance to Anthrax. Bacillus Anthracis spores also may live in soil for years. The only way to destroy the spores is by steam sterilization or burning. There has been no evidence of person to person transmission of th .....
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Bacillus Anthracis 2
.... where workers must handle animal carcasses. The livestock version of the vaccine is very effective, however. The vaccine for both animals and humans is composed of sublethal amounts of toxin that induce formation of protective antibody. Frequent boosters are necessary to maintain resistance to Anthrax. Bacillus Anthracis spores also may live in soil for years. The only way to destroy the spores is by steam sterilization or burning. There has been no evidence of person to person transmission of the d .....
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Bacteria 2
.... molecules, which are absorbed by the bacterial cells. Parasites live on or in living organisms, and may cause disease. A few types of bacteria are Autotrophic, they can synthesize the organic nutrients they require from inorganic substances. Autotrophic bacteria are either photosynthetic or Chemosynthetic. The photosynthetic bacteria contain chlorophyll that are different from the plant chlorophyll. In bacterial photosynthesis, hydrogen is obtained by the splitting of compounds other than water. Therefo .....
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