Skip to main content

Home/ 7E Science ASB/ Group items tagged Media 4

Rss Feed Group items tagged

Abraham H

Forensic Techniques [Media 4] - 0 views

  • RFLP is a technique for analyzing the variable lengths of DNA fragments that result from digesting a DNA sample with a special kind of enzyme. This enzyme, a restriction endonuclease, cuts DNA at a specific sequence pattern know as a restriction endonuclease recognition site. The presence or absence of certain recognition sites in a DNA sample generates variable lengths of DNA fragments, which are separated using gel electrophoresis. They are then hybridized with DNA probes that bind to a complementary DNA sequence in the sample. RFLP was one of the first applications of DNA analysis to forensic investigation. With the development of newer, more efficient DNA-analysis techniques, RFLP is not used as much as it once was because it requires relatively large amounts of DNA. In addition, samples degraded by environmental factors, such as dirt or mold, do not work well with RFLP.
  • PCR Analysis Polymerase chain reaction (PCR) is used to make millions of exact copies of DNA from a biological sample. DNA amplification with PCR allows DNA analysis on biological samples as small as a few skin cells. With RFLP, DNA samples would have to be about the size of a quarter. The ability of PCR to amplify such tiny quantities of DNA enables even highly degraded samples to be analyzed. Great care, however, must be taken to prevent contamination with other biological materials during the identifying, collecting, and preserving of a sample.
  • Short tandem repeat (STR) technology is used to evaluate specific regions (loci) within nuclear DNA. Variability in STR regions can be used to distinguish one DNA profile from another. The Federal Bureau of Investigation (FBI) uses a standard set of 13 specific STR regions for CODIS. CODIS is a software program that operates local, state, and national databases of DNA profiles from convicted offenders, unsolved crime scene evidence, and missing persons. The odds that two individuals will have the same 13-loci DNA profile is about one in a billion.
  • ...1 more annotation...
  • Mitochondrial DNA analysis (mtDNA) can be used to examine the DNA from samples that cannot be analyzed by RFLP or STR. Nuclear DNA must be extracted from samples for use in RFLP, PCR, and STR; however, mtDNA analysis uses DNA extracted from another cellular organelle called a mitochondrion. While older biological samples that lack nucleated cellular material, such as hair, bones, and teeth, cannot be analyzed with STR and RFLP, they can be analyzed with mtDNA. In the investigation of cases that have gone unsolved for many years, mtDNA is extremely valuable. All mothers have the same mitochondrial DNA as their offspring. This is because the mitochondria of each new embryo comes from the mother's egg cell. The father's sperm contributes only nuclear DNA. Comparing the mtDNA profile of unidentified remains with the profile of a potential maternal relative can be an important technique in missing-person investigations.
Emma Chowdhury

Forensic DNA technology: A powerful tool for judicial reform | Science and Technology, ... - 0 views

  • Recent advances in forensic DNA testing are now paving the way for reforming the manner by which cases are resolved in courts of law through the way suspected offenders are apprehended during a criminal investigation. Firstly, the availability of new markers which are more variable across different populations, adds to the increased power of discrimination once more genetic markers are used. From the time when DNA testing only involved seven to nine genetic markers to evaluate if crime scene evidence matches a suspect’s profile, as well as to determine relationships, to the current battery of 21 autosomal markers and 23 male-specific markers, the capacity of DNA profiling to differentiate individuals has increased significantly. The use of automated and expert systems for large-scale analysis has also been found to reduce manual errors and to increase output per unit time. The use of several dyes in a single multiplex system provides more information from the same amount of genetic material compared to reactions targeting only one genetic marker but requiring the same amount of DNA that was common in the early 1990s.
  •  
    This is about how they have new technology for forensic DNA sciences, so they make less mistakes and can find the person quickly. For example, they now have automatic systems to test DNA.
  •  
    What is the media type???
Sejin C

20 Animals That Have Been Cloned - 1 views

  • 20 Animals That Have Been Cloned
  • 1. Carp (Featured above: A common carp, as-yet-uncloned) An Asian carp was cloned successfully in 1963; ten years later, scientist Tong Dizhou also cloned a European crucian carp.
  • 2. Dolly the Sheep Dolly saw the light of day in 1996. She lived until the age of six. The first cloned mammal, Dolly is considered to be a great success. Later, several hundred other Dollies were cloned.
  •  
    There were many successful cloning.
  •  
    I am not entirely sure which category of media this falls under. Doesn't seem to meet the requirements of any of teh 4 media types we have asked you to research.
  •  
    Animal Cloning.
Yusuke K

Stem cell cutting-edge tech Media 4 - Yusuke - 0 views

  •  
    Is this your "technique" ? Then you will need a bit more detail on the actual technique. Also please TAG your articles appropriately!
  •  
    Can you tag this properly aswell.
Romy Kedem

EBSCOhost: Weighing in on Genetic Engineering and Morality: Students Reveal Their Idea... - 0 views

  •  
    what media type is this? Your tags are not correct
1 - 5 of 5
Showing 20 items per page