PCR, gene cloning, DNA profile.

Polymerase chain reaction replicates a given segment of DNA so that can be used in several applications including electrophoresis and genome sequencing. If DNA is found on a subject, it can practically be replicated a million times over so that you don't rely simply on what was found. Given that DNA is fragile, if you only have one copy, it could get damaged, hence this method is used to copy it as many times as needed.

1. PCR is used for amplification of a particular gene. We want to amplify a particular gene to study its effects (we can place the gene into a vector and insert the vector into a bacteria to study the effects of the gene we amplified) or we can create proteins from the particular gene (the protein coding region of a gene will encode for proteins through the process of translation).

Furthermore, if we know the location of the gene of interest, we can design primers to direct PCR machinery to cut at the specific portion of the genome we want. Gene cloning, on the other hand, mostly deals with recombinant DNA technologies. Gene cloning is mostly used for determining the whole genome of an organism, production of recombinant proteins, to make transgenic animals, and gene therapy.

2. The percentage of protein coding regions of our whole genome is actually very small! Our whole genome is made up of many other regions of DNA including introns, repetitive sequences, and regulatory regions. These regions of the DNA do not encode directly for proteins, but may help regulate other aspects of transcription and translation, and help make an individual unique! For instance, the repetitive regions can be used in PCR to do paternity tests, for instance, or determine the criminal in a crime scene.

Answer 1.

Some applications of PCR in the biotechnology

There is a broad range of PCR applications. Some of them include preparation of molecular markers, in monitoring the genetic engineering and gene therapy experiments, DNA fingerprinting, diagnosis of genetic diseases and many others. For instance, DNA fingerprinting: The DNA amplification via PCR is possible for characterization of an individual from a trace amount of blood, hair seminal fluid. Thus, plays a crucial role in the identification of criminals, solving parental disputes.

Two advantages of PCR over gene cloning

Gene cloning requires a large amount of DNA (in micrograms) to be extracted from many cells to study a fragment of DNA or gene. In contrast, PCR needs DNA in nanograms to study a gene. The time needed for the entire gene process can range from days to months whereas PCR requires only a few hours to amplify DNA to million fold.

Answer 2.

Variability in non-coding or introns regions (such as mini-satellites) is also indicative of differences in DNA profiles between individuals. Therefore, one person comprises families of these repeats that is different from other, and these regions make one person DNA profile as unique.