PCR (polymerase chain reaction) is a relatively new advance (1980's) but it has a great impact in our lives. Specifically, in forensic science, PCR is useful in many sorts of crimes . Up until the PCR method, in order to identify a person forensic scientists would use fingerprints or some other ambiguous methods like teeth marks etc. But now, with PCR, we can compare the genetic material found on a crime scene and compare it with a suspect's genetic material, definitively concluding whether they are the same person or not. The way this works is that we collect a sample from the crime scene with DNA and then PCR amplifies the quantity of DNA in that sample. One of the apparent advantages of this method is that PCR works with even a very small sample, often not even a single cell is required. This makes crime scenes full of information. Hence, succinctly, PCR has helped modern forensic science in that:
1) its results are more definitve than traditional identification methods and subject to less ambiguity
2) it is relatively fast
3) new pieces of evidence can be of value (like some hair cells) and identify the crominal in cases that in older times would be impossible to solve.
Answer:
A genetic sequence, the TATA box, is a transcriptions start site and initiates transcription through the formation of RNA polymerase. Negative regulation may inhibit the initiation of transcription and/or repress gene expression.
Explanation:
proteins called transcription factors bind to the TATA box, this triggers RNA polymerase to start synthesizing RNA to DNA
<span>The lymphoid tissues of the intestinal tract are collectively referred to as GALT.Gut-associated lymphoid tissue (GALT) is a component of the mucosa-associated lymphoid tissue (MALT) which works in the immune system to protect the body from invasion in the gut.</span>
<span>The correct answers are that it lacks cells, DNA, and cannot maintain homeostasis. It doesn't have any organic matter and homeostasis is impossible because it would turn off eventually. It doens't have DNA and it doesn't reproduce. It's just plasma and it is not a living being, it just moves because of the chemical reactions that occur. </span>
Answer:
1. lytic/losigenic cycle
2. Restriction enzymes (breaks) and DNA ligase (joins)
3.mitosis (creation of twin daughter cells)
4. mitosis had helped humans with cell growth and repais (and keeps a steady supply of new cells)
Explanation:
it first goes through the lytic cycle where one bacterium inserts it's own dna into a host (human cell) and into the human DNA and it starts multiplying inside human cells in the lysogenic cycle
