Thursday, 25 April 2013

fatima nuria and lidia


HOW GENETIC PROFILING IS USED TO IDENTIFY CRIMINALS AND TO DO PATERNITY TESTS.


Since its debut in Florida courtroom in 1967, DNA “fingerprinting” evidence has captured the attention of prosecutors, defense attorneys and the popular press. As the newest method of establishing identity, DNA profiling has been widely touted as “the most powerful, most accurate place of forensic evidence that´s ever been created”.

 DNA profiling was developed by molecular biologists for use in the genetic research of inherited diseases. DNA testing has since been heralded as the answer to legal quandaries ranger from murder to paternity. Using minute traces of genetic material extracted from seemingly harmless sources such as a single strand of hair, a speck of dried blood , a drop of saliva, or a semen stain on a bed sheet.


DNA profiling is a technique employed by forensic scientists to assist in the identification of individuals by their respective DNA profiles. DNA profiles are encrypted sets of numbers that reflect a person's DNA makeup, which can also be used as the person's identifier. DNA profiling should not be confused with full genome sequencing.  It is used in, for example, parental testing and criminal investigation.
Although 99.9% of human DNA sequences are the same in every person, enough of the DNA is different to distinguish one individual from another, unless they are monozygotic twins. DNA profiling uses repetitive  sequences that are highly variable, called variable number tandem repeats (VNTRs), particularly short tandem repeats (STRs). VNTR loci are very similar between closely related humans, but so variable that unrelated individuals are extremely unlikely to have the same VNTRs.
Familial DNA searching
Familial DNA searching  is the practice of creating new investigative leads in cases where DNA evidence found at the scene of a crime (forensic profile) strongly resembles that of an existing DNA profile (offender profile) in a state DNA database but there is not an exact match. After all other leads have been exhausted, investigators may use specially developed software to compare the forensic profile to all profiles taken from a state’s DNA database in order to generate a list of those offenders most likely to be a close relative of the forensic profile.To eliminate the majority of this list, crime lab technicians conduct Y-STR analysis that confirms the familial relationships suggested by the first list. Using standard investigative techniques, authorities are then able to build a family tree. The family tree is populated from information gathered from public records and criminal justice records. Investigators rule out family members’ involvement in the crime by finding excluding factors such as sex, living out of state or being incarcerated when the crime was committed. They may also use other leads from the case, such as witness or victim statements, to identify a suspect. Once a suspect has been identified, investigators seek to legally obtain a DNA sample from the suspect. This suspect DNA profile is then compared to the sample found at the crime scene, in accordance with well-established and constitutionally accepted practices, to definitively identify the suspect as the source of the crime scene DNA.

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Paternity tests.      
Parental testing is the use of genetic fingerprinting to determine whether two identical individuals have a biological parent child relationship. There are lots of methods to do it, blood group, analising the proteins...
The genetic paternity test is made by comparing the DNA of both individuals. The human being inherit one allele from the mother and another from the father. A son must have for each locus (the position of a chromosome in the DNA) one allele from the father.
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How we can take a sample?
A professional in medicine take some blood drops from the finger with a special card to be analised in a laboratory.In some cases we can extract the sample from the mouth.
Can we make the test during the pregnancy?
Yes, but only after the sixteenth week.In this case the gynaecologist extract, under ecographic supervision, a little sample of the amniotic liquid that contains cells that have being produced by the foetus and are compared with the paternal sample.
ADVANTAGES AND DISADVANTAGES OF GENETICALLY MODIFIED FOOD.

Now a days, the genetically modified food had increase its popularity not only for scientist, also for the consumers.
HOW WE CAN MODIFY FOOD?
This is a recombinant DNA technology, that consist of isolating a gene of an organism and inserting it into a different one. Ex: in the countries from the noth, as Norway, there are cold temperatures so most of the plants or vegetables, like tomatoes, cant grow, so we can genetically modify a tomato to support this cold temperatures extracting the gene to support cold temperatures and introducing it in the DNA of the tomato.





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ADVANTAGES.
  • We can consum food with more vitamins, minerals and proteins and some of them with less quantity of fats.
  • More resistance farmings to the attacks of different kind of virus or insects without the necesity of use pesticides and chemical products, that is an ecomonic save of money and more respecfull with the enviroment.
  • Higher conservation in fruits and vegetables.
  • Increase in the production.
  • The farmings are resistance to the escarce of water.


Disadvantages of genetically modified food.


The safety of such products is not verified yet, in fact, we are the lab rats to test the safety of such technology. Genetically engineered food is being consumed daily with no thorough research of its potential threats on human health.
Genetically modified ingredients can cause cancer. Food and water contaminated with genetically engineered material could increase the growth of malignant tumours upon contact with humans.
It could raise new allergy outbreaks in humans. People may find that they are now allergic to other food products – people because they contain a gene from the allergen they have. It was found that a genetically engineered soya bean containing Brazilian nut protein was allergenic to humans and was withdrawn from production.
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Under-Developed countries becoming more dependent on other communities. 
You are ‘not’ what you eat any more. Genetic engineering allows introducing animal products in plants which could raise issues for those with dietary restrictions, like vegetarian or vegans.
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It is un-natural way of producing food. There will always be unknown long term effects to the ecosystem and biodiversity when inducing unnatural ways to change the natural traits of crops.

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Adverse effects on the immune system. Feeding mice engineered food for 30 days caused an immune reaction and altered the number of cells that regulated the immune functions in the body.
Pesticide resistant food can create super-creatures! modified genes in engineered crops that resist pesticides can transfer to insects and pests; making them pesticide resistant.
Genetically modified products cannot be recalled. Altered genes in engineered food will multiply through generations, passing with it any unknown damaging trait to the future population.

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It may affect the human digestive system in a number of ways. The incorporation of substances that may interact badly with one another in food or in fact be poisonous to people may happen. The modification of certain genes may make some plant substances difficult to digest at all.
The effects of genetic food engineering could be irreversible.







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