Dna Discovery Essay

Dna Discovery Essay
As the instructions for all living cells, DNA is a complex molecule and the basis of biology. The structure of DNA is the same for all organisms.
(Fredholm, 2003) The journey to understanding DNA began in 1866 when Augustinian monk Gregor Mendel discovered the basic principles of
genetics. Although the scientific community did not fully appreciate or credit his work in his lifetime, Mendel is now considered the father of
genetics. Mendel's advanced experiments with pea plants between 1856 and 1863 identified the existence of dominant and recessive traits. He
unknowingly described genes as the 'invisible' factors for providing a predictable phenotype. Although credited to American–English duo James Watson
and Francis Crick, the next...show more content...
Rosalind Franklin's work using X–ray diffraction also led to the discovery of the DNA structure for which Watson, Crick and Maurice Wilkins shared
Nobel Prize recognition in 1962. (Pray, 2008) Her work included establishing the water content of DNA using X–ray crystallography and fuzzily
revealing the pattern of a helical structure with "Photography 51." (Fredholm, 2017) Franklin was the first person to view DNA, but since she was a
woman credit was not granted in her name. She also did not qualify to receive the Nobel Prize as she died 4 years earlier, in April 1958. The
Hungarian–born American biochemist Erwin Chargaff contributed in solving the mystery regarding the four nitrogenous bases of DNA. In 1949, he
showed that amounts of these bases are always balanced, even if different organisms had different amounts of DNA. This specified a 1:1 ratio of purine
to pyrimidine base in each nucleotide and creates a consistent width throughout the DNA molecule. (Fredholm, 2003) Adenine and guanine are larger,
double–ringed purines. Thymine and cytosine are smaller pyrimidines. Adenine will only bond with a thymine in DNA; cytosine only to guanine. The
complementary bases are paired together with hydrogen bonds. (BiologyWise, 2017) Chargaff's rules were solidifying insight for Watson to recognize
a helix outside of smooth sugar–phosphate backbone and congruent lengths of A–T and C–G bonds in February 1953.
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DNA Essay
To understand how genetic characteristics and DNA work together, we must look at DNA and understand how it is structured. The sugars adenine (A),
thymine (T), cytosine (C) and guanine (G) are nucleotide bases, the building blocks of DNA. These sugars interact with each other, forming DNA
strings/chains. An example is GATCATCCG, this string serves as a manual for building aprotein. The DNA contains the entire building instruction, the
blueprint to construct an organism (animals, humans, plants or microorganisms). However, this is a very simple overview and to do DNA truly
justice, we need to get into more detail.
Organisms make protein after reading the manual of making RNA which is an authentic copy of DNA. The body translates the...show more content...
According to the report, the classification of erroneous synthesis is, any disturbance in the translation of the coding sequence into functioning protein.
Amino–acids can become compromised when built, resulting from transcription errors when DNA reads the manual to make RNA. Aberrant splicing
may occur, faulty modifications and folding errors are possible too. On the other hand, correctly synthesized polypeptides that fail to fold correctly are
also included.
Although these errors may take place in all steps of the protein synthesis, from the copying to the folding process; the consequences are widespread.
There is not much knowledge about this yet. Although, there is enough evidence that faulty protein synthesis results in lesser fit organisms. The
consequences of erroneous protein synthesis can be minor, which might only affect the cellular material that is responsible for the rejuvenation of
cells, causing deformed cells, or excessive cell growth. These irregularities might affect the organism itself, but might not transfer into the genetic
material used for reproduction. With other words, when faulty protein is built, or folded wrong, it results in deformation of cells/organs and/or affects
the quality of the genetic material of the organism. Very little was known, only 5%, the research started 45 years ago. However, the publication only
elaborates that errors can be divided into two categories. Category

Dna Replication Essay
Since we discovered that DNA is in the nucleus in every single cell, we're curious about how exactly DNA can be replicated in a way that can keep
our identity, including our characteristics. This could be described after learning about DNA and its very individual characteristics, along with
transcription and translation, which are the two steps of DNA replication. These steps can determine our characteristics, as well as our personalities.
DNA is mostly made of adenine, thymine, guanine and cytosine. These all make hydrogen bonds, and that's only if it's connected to the correct base.
An example of this would be when thymine connects to adenine and guanine connects to cytosine. Though, since this is mRNA being created, adenine
would connect...show more content...
The DNA helicase latches on to the DNA molecule, unzipping the double helix, letting enzymes break the hydrogen bonds that connect the base pairs.
Also, complementary nucleotides that are floating around and about in the nucleus form hydrogen bonds according to their pairs: thymine to adenine
and guanine to cytosine. Due to the hydrogen bonds being more breakable, the DNA is much easier to "unzip" for replication. In the cytoplasm you
can also find tRNA. tRNA contains a 3 nucleic code on one side and on the other side, there's a special protein on the other. In the cytoplasm, mRNA
attracts ribosomes that have a similar 3 letter code of tRNA. The amino acids from tRNA then bond with the mRNA, which then creates a protein chain
when a start codon or Methionine is reached. This chain will eventually stop once the stop codon is reached. This will then create a completed protein.
In conclusion, even through replication, we are still able to keep our characteristics due to the stationary and unchanging method of replication, which
is where we keep the same genetic coding. With the steps of DNA replication, this determines our characteristics, along with our personalities. The more
we continue the studying of genetics, we may one day be able to cure disorders before the person is even born or

Dna Replication Essay examples
DNA REPLICATION
WHAT IS DNA?
DNA is a molecule that has a repeating chain of identical five–carbon sugars (polymers) linked together from head to tail. It is composed of four ring
shaped organic bases (nucleotides) which are Adenine (A), Guanine (G), Cytosine (C) and Thymine (T). It has a double helix shape and contains the
sugar component deoxyribose.
THE PROCESS OF DNA REPLICATION
How DNA replicates is quite a simple process. First, a DNAmolecule is "unzipped". In other words, it splits into two strands of DNA at one end of
the DNA molecule. This separation will cause a formation of a replication fork.
After the replication fork has been established the strands of DNA are ready for the next stage. On each strand is a sequence...show more content...
&#61623; The first discovery Chagraff made was that the amount of adenine present in all DNA molecules is equal to the amount of thymine.
&#61623; The second discovery Chagraff made was that the amount of guanine was equal to the amount of cytosine.
&#61623; The third discovery Chagraff made was that the amount of adenine plus thymine often differs greatly from the amount of guanine plus
cytosine.
HOW THE IMAGE OF DNA WAS FIRST DISCOVERED
After Chagraff's discoveries, two British scientists by the name Rosalind Franklin and Maurice Wilkens were able to apply his observations. Thus,
these two scientists were the first ones to discover the image of what a DNA molecule actually looked like in three–dimension.
How these scientists manage to obtain the image of a DNA molecule was by the use of "x–ray crystallographic analysis". In this process, DNA
molecules are bombarded with a x–ray beam. These x–rays encounter atoms, which in turn causes their paths to bent or diffract. The pattern created by
the sum of total of these diffractions are then captured on a photographic film. The pattern is then interpreted into the image of the molecule through
careful analysis. Thus, because of this research it led to the first theory and model structure of DNA.

MAURICE WILKENS
Maurice Wilkens was born in the year 1916 and is a British

Dna Essay
DNA in Forensic Science
DNA is the genetic blueprint for life because it contains the instructions that oversee the development of an organism. Taking samples of DNA and
analyzing them to determine if they come from the same individual is known as DNA profiling. Investigators gather items such as hair, saliva, semen
and blood that could contain DNA from a crime scene. DNA profiling is also used in paternity testing, victim identification andevolution research.
First, the collected DNA samples are isolated. Next, selected sequences from each DNA sample are replicated to produce a large sample of DNA
fragments. Finally, the enlarged DNA samples are compared to other samples to determine whether the samples came from the same person or...show
more content...
The mitochondria of our cells and those of every other eukaryote are descendants of those smaller prokaryotes, so are the chloroplasts of plants and
algae.
Biological Diversity Evolution Biological diversity evolution combines the millions of species that live on our planet, and the genetic differences in
those species. Biodiversity plays a key role in maintaining healthy ecosystems and sustaining ecosystem services to the growing human population. It
also refers to the massive amount of diverse ecosystems in which species form distinctive communities that interact with each other. One example of
biological diversity evolution is the North American Garter Snake. This snake lives primarily in the water but its closely related species lives
primarily on land. This shows the biological diversity evolution on close related species that have evolved in different ways. (Campbell Essential
Biology 2013) Another example is the wheat plant which is the world most cultivated plant. Sexual selection in which females choose mates to
reproduce based on color has contributed to biological diversity evolution as well. Another example is the procreation of the spotted skunks, the
western spotted skunks breed in the fall while their closest relative that lives in the east breeds late in the winter. (Campbell Essential Biology 2013)
Plant and Animal Evolution According to the fossil record, there have been 4 periods of plant evolution. (Campbell Essential

Dna And Protein Synthesis Essay
DNA and Protein Synthesis
One of the most fundamental properties of any and all living organisms is that of reproduction. As we all have learned, organisms inherit their genetic
information defining their structure and functions from their parents. Similarly, all cells come from preexisting cells, so the genetic information is
duplicated and pass from the parent to the new cell of each division.
DNA is the term that is used in biology, as well as several other parts of your everyday life. We all know that DNA is a part of our bodies, but may
wonder what exactly is DNA. DNA which is also known as deoxyribonucleic acid, which is the genetic material of a cell. DNA is considered to be
the molecule of life, and aides in the determination of our physical characteristics. DNA is present in all living organisms.
It is said that the process of protein synthesis is controlled by the DNA molecules. Proteins are used for growth and repair, as well as enzymes. Thus,
DNA is able to apply some controlling influence over the cells as a whole, and ultimately the organism as well. In DNA, the segments which hold the
vital key to this process are referred to as the genes.
In the early 1940's, two American geneticists by the names of George Wells Beadle, and Edward Lawrie Tatum provided one of the first vital clues.
While they were working with fungi, more specifically Nuerospora and Penicillium, they found information regarding genes and how they direct the
formation of enzymes through the

Essay On DNA Discoveries
Discoveries in DNA, cell biology, evolution, biotechnology have been among the major achievements in biology over the past 200 years with
accelerated discoveries and insights over the last 50 years. Consider the progress we have made in these areas of human knowledge. Present at least
three of the discoveries you find to be most important and describe their significance to society, health, and the culture of modern life.
DNA per medical dictionary is defined as A nucleic acid that carries the genetic information in cells and some viruses, consisting of two long chains of
nucleotides twisted into a double helix and joined by hydrogen bonds between the complementary bases adenine and thymine or cytosine and guanine.
DNA sequences are...show more content...
Thus, proteins that are formed play certain roles as the body synthesizes those specific proteins for the exact job at the exact time. Some of the
diseases affected by this are sickle cell and malaria.
Sickle cell: One of the first inherited diseases to be unraveled at the level of DNA was sickle–cell anemia which is defined as abnormal,
crescent–shaped red blood cells that results from a single change in the amino acid sequence of the cell's hemoglobin, which causes the cell to contort,
especially under low–oxygen conditions. (medical dictionary, 2017) Also, called drepanocyte, meniscocyte. Also, this blood disorder mostly affects
Africans and natives of the Mediterranean region are those who are affected by malaria. A single mutation in thegene for the blood protein hemoglobin
can affect its ability to transport oxygen around the body. People who inherit two copies of the same mutation, one from each parent, have severe
symptoms.
Malaria: However, those who inherit just one copy of the mutation do not suffer too badly; in fact, they are resistant to malaria which defined as an
infective disease caused by sporozoan parasites that are transmitted through the bite of an infected Anopheles mosquito; marked by paroxysms of chills
and fever. The discovery told geneticists much about evolution and how harmful mutations can increase to relatively high levels within a population
provided they confer some advantage. By understanding how

Dna Editing Research Paper
Body/Hypothesis
Where did DNA editing come from and how does it work?
DNA editing was discovered thanks to the clash between bacteria and viruses. Bacteria and viruses have been fighting each other since life on Earth
began. During an invasion of a cell, the virus inserts its own genetic code(RNA) into the bacterium and takes it over to use as a factory to replicate
itself. The bacterium, meanwhile, tries to resist but ends up failing most of the time because it has weak, and insufficient tools to protect itself. Some
bacteria however, through natural selection or chance, survive the attack and save part of the virus's genetic code(Kurzgesagt, 2016). The RNA of the
virus is then saved in the bacterium's own genetic code in a DNA archive...show more content...
A scientist named Anthony James encountered this problem when he programmed mosquitoes to no longer transmit malaria. Though years of hard
work, James was able to create a mosquito resistant to the parasite by adding genes that made it impossible for the malaria parasite to live inside of it.
After this success, Anthony James was met with the problem of how he was going to spread this new gene(Kahn, 2016). Now that you've got a
mosquito resistant to malaria, how is this gene going to replace the malaria in mosquitoes carrying the parasite? At first there was the idea that ten
times the the amount of mosquitoes in the area should be released in the hopes that the gene would be passed on. This idea, however, would not be
beneficial to the people living in the area where the mosquitoes were being released(Kahn, 2016). Months later, James received an email from a
biologist named Ethan Baer about a genetic tool that not only ensured that a genetic trait would be inherited, but that it would spread exponentially
quickly. To test the reliability of this tool, the scientists engineered two mosquitoes to not only carry the anti–malaria gene, but also the new tool(Kahn,
2016). They set up the test in such a way that any mosquitoes that inherited the anti–malaria gene would not have the ordinary white eyes, but red eyes.
This made it easier for scientists to distinguish between a mosquito with the gene and without it(Kahn, 2016). After putting two of the red–eyed
mosquitoes in a box with 30 ordinary mosquitoes to breed, scientists found that after two generations, not only had 38,000 mosquitoes been born, but
all of them had red eyes. According to mendelian genetics this is not possible because only half of the DNA from each parent is inherited by the
offspring(Kahn, 2016). This means that there should have been

Dna Essay
Abstract
This paper explores the history and some interesting facts about DNA. The last couple centuries have seen an exponential growth in our knowledge of
DNA. The history of the DNA can be traced back to multiple devoted scientist. This article attempts to summarize, and review the basic history ofDNA
while providing some fascinating information about it.
A Brief Historic Review Throughout the early 19th and 20th century, many scientists have studied deoxyribonucleic acids in order to attain higher
understanding over the matter. Johann G. Mendel had figured out and understood the laws of heredity. Friedrich Miescher amazingly discovered DNA
in 1869, even though scientists did not understand DNA was the genetic material...show more content...
The pictures were shown to James Watson andFrancis Crick by Maurice Wilkins. They were then able to confirm their theory about the 3D structure
of DNA. In 1962, they were awarded the Nobel Prize in Physiology or Medicine for solving the structure of DNA. The Nobel committee could not
award it to Franklin because the Nobel prize could only be shared by three people and also because she was already dead (DNA from the Beginning,
2011)
Origin of the Four Bases' Names The four names of the nitrogenous bases of the DNA are adenine, thymine, guanine, and cytosine. The word
"adenine" was created in the 19th century in German from the Greek words "adД“n" "gland" and "in". The word "cytosine" was coined in the 19th
century from the German word "cytosin" from cyto– "cell", –ose and the chemical suffix –ine. The word "guanine" comes from the English words
"guano" and "ine" and was also created in the 19th century. The word "thymine" comes from words "thymus" and the suffix –ine.
Interesting Facts Although DNA molecules seem minuscule, if all the DNA in a human body was unwound and placed from end to end, it would
cover about 10 billion miles. That's approximately the same distance as traveling from the Earth to Pluto and back. (Helmenstine, 2017). "If a person
typed 60 words per minute, eight hours a day, it would take approximately 50 years for them to type the human genome" (Kawasaki, 2010). Scientist
have calculated that DNA has a 521–year half–life, which

DNA testing Essay
DNA testing has overthrown the way police collect evidence in a number of criminal cases, especially rape and murder and consequently had a large
impact on many past cases. However there are many disadvantages to DNA testing, such as a challenge of accuracy, the costs of DNA testing and the
possible misuse of DNA. The prospect of a national DNA database in Australia has been heavily criticised withcomplaints of invasion of privacy and
stigma against those with terminal diseases.
Deoxyribonucleic acid, or DNA as it is most commonly known, is a strand of molecules found within the cell nucleus of all living things. It is called a
"genetic fingerprint" because each is different to the other and everyone, apart from identical twins, have...show more content...
Another downside to the use of DNA is the misuse of results. Victims with AIDS feel that they might be stigmatised if their DNA is stored in a
national database and it could be used against them.
The prospect of a genetic database in Australia has been raised recently. The federal police are pushing for a national database to help solve crime
and are asking for legislation to be allowed to collect DNA samples from people accused, or suspected of committing an offence (the Australian,
06.12.1997 see appendix one)
The proposal has sparked a moral dilemma. Victoria has had a DNA database since 1992 with the reasoning that, if a suspect is cleared, their DNA
must be erased off the list. However, recently Victorian government has allowed police to collect samples from more suspected criminals, not just
those accused of murder, serious assault or rape. Now they are allowed to collect from those accused of drug trafficking, arson causing death and
aggravated burglary.
Privacy is also another big issue surrounding the plans for a database. Chairman of the New South Wales privacy council says that the prospect of a
genetic database is a "cavalier disregard for people's privacy"
Recently it was passed that all states, apart from Western Australia have the right to compose a DNA database (The Sydney Telegraph, 22.04.2001 see
appendix two) and already there had been a few flaws found. With

DNA Essay example
DNA is a term that has been used in science as well as in many parts of daily life. The general public knows that DNA is a part of our bodies but
they may wonder what exactly is DNA? DNA is a term used for deoxyribonucleic acid and it is the genetic material of all organisms, it is the
molecule of life and it determines all of our physical characteristics. DNA is present in every single form of life. More than 50 years after the science
of genetics was established and the patterns of inheritance were clarified, the largest questions remained unanswered: How are the chromosomes and
their genes copied exactly from cell to cell, and how do they direct the structure and behavior of living things?
Two American geneticists, George...show more content...
"To make a new, identical copy of the DNAmolecule, the two strands unwind and separate at the bases which are weakly bound; with more
nucleotides available in the cell, new complementary bases can link with each separated strand, and two double helixes result." (Caldwell) Since the
"backbone" of every chromosome is a single long, double–stranded molecule of DNA, the production of two identical double helixes will result in the
production of two identical chromosomes.
The DNA backbone is actually longer than the chromosome but is tightly coiled up within it. This packing is now known to be based on minute
particles of protein known as nucleosomes, that can only be seen under the most powerful electron microscope. The DNA is wound around each
nucleosome to form a beaded structure.
The structure is then further folded so that the beads associate in regular coils. Thus, the DNA has a "coiled–coil" configuration.
After the discoveries of Watson andCrick, the question that remained was how the DNA directs the formation of proteins, compounds central to all the
processes of life. Proteins are not only the major components of most cell structures, they also control virtually all the chemical reactions that occur in
living matter. The ability of a protein to act as part of a structure, or as an enzyme affecting the rate of a particular chemical reaction, depends on its
molecular shape. This shape, in turn,

DNA Essay
DNA
After staying on the plant Earth reaching the human genetic technology, I have come up with this report the four things I am going to talk about in this
report are: 1) What is the chemical basis of the plant Earth 2) What do human mean by
"genetic technology" and how is it possible 3) How have human used this technology 4) Are humans concerned about this technology
1)The chemical basis of the plant earth is deoxyribonucleic acid (generally shortened to DNA), it has the shape of a long twisted ladder each rung of this
ladder is made up of a pair of chemical bases, the information that human body need to make proteins is coded and contained in the order of these
bases along the length of the DNA ladder. All DNAmolecules...show more content...
By using this technology it is possible to alert characteristics of living organisms in specific ways. The chemical languages of DNA in all living thing
are the same so it is possible to take one gene from one living thing and transfer into another living thing. To give an animal permanent genetic change
the new gene must be inserted into the single cell embryo from which all the cell's will develop in the adult animal's body. It is much difficult to
introduce DNA into plant cells. So humans take one microbe that infects the plant normally and puts it in a virus or bacterium and make the it carries the
DNA into the plant cell.
3)Humans has already used 'genetic technology' and here are the three examples of the living thing's human have used 'genetic technology' on. First
example is the environmentally friendly cotton (cotton is any of various shrubby plants grown for the soft, white, downy fibers surrounding oil–rich
seeds' humans use the fibers to make cloth). On the cotton there is a kind of pest called cotton bollworm, it ate the fiber to live. Each year humans
have to spend a lot of money on pesticides to kill those worms. Now with 'genetic technology' humans are trying to make bollworm resistant cotton.
Humans have found a bacterium that kills the bollworm, they are going to put this new gene into the cotton so it will produce a protein that kills the
bollworm, but the protein is harmless to all the other living things.

Dna Essay
The Interesting History and Facts of DNA
Kevin T. Hoang
James Martin High School
Abstract
This paper explores the history and some interesting facts about DNA. The last couple centuries have seen an exponential growth in our knowledge of
DNA. The history of the DNA can be traced back to multiple devoted scientist. This article attempts to summarize, and review the basic history ofDNA
while providing some fascinating information about it.
A Brief Historic Review Throughout the early 19th and 20th century, many scientists have studied deoxyribonucleic acids in order to attain higher
understanding over the matter. Johann G. Mendel had figured out and understood the laws of heredity. Friedrich Miescher discovered DNA...show more
content...
The pictures were shown to James Watson andFrancis Crick by Maurice Wilkins. They were then able to confirm their theory about the 3D structure
of DNA. In 1962, they were awarded the Nobel Prize in Physiology or Medicine for solving the structure of DNA. The Nobel committee could not
award it to Franklin because the Nobel prize could only be shared by three people and also because she was already dead (DNA from the Beginning,
2011)
Origin of the Four Bases' Names The four names of the nitrogenous bases of the DNA are adenine, thymine, guanine, and cytosine. The word
"adenine" was created in the late 19th century in German from the Greek words "adД“n" "gland" and "in". The word "cytosine" was coined in the late
19th century from the German word "cytosin" from cyto– "cell", –ose and the chemical suffix –ine. The word "guanine" comes from the English words
"guano" and "ine" and was also created in the 19th century. The word "thymine" comes from words "thymus" and the suffix –ine.
Interesting Facts Although DNA molecules seem minuscule, if all the DNA in a human body was unwound and placed from end to end, it would
cover about 10 billion miles. That's approximately the same distance as traveling from the Earth to Pluto and back. (Helmenstine, 2017). If a person
typed 60 words per minute, eight hours a day, it would take approximately 50 years for them to type the human

DNA EXTRACTION Essay
Much can be learned from studying an organisms DNA. The first step to doing this is extracting DNA from cells. In this experiment, you will isolate
DNA from the cells of fruit. Materials (1) 10 mL Graduated Cylinder(2) 100 mL Beakers15 cm Cheesecloth1 Resealable Bag1 Rubber Band (Large.
Contains latex pleasewear gloves when handling if you have a latex allergy).Standing Test TubeWooden Stir StickFresh, Soft Fruit (e.g., Grapes,
Strawberries, Banana, etc.) ScissorsDNA Extraction SolutionIce Cold EthanolYou Must ProvideContains sodium chloride, detergent and waterFor ice
cold ethanol, store in the freezer 60 minutes before use. Procedure If you have not done so, prepare the ethanol by placing it in a freezer for
approximately 60 minutes....show more content...
Let the test tube sit undisturbed for 2 – 5 minutes. You should begin to see air bubbles form at the boundary line between the ethanol and the filtered
fruit solution. Bubbles will form near the top, and you will eventually see the DNA float to the top of the ethanol. Gently insert the stir stick into the
test tube. Slowly raise and lower the tip several times to spool and collect the DNA. If there is an insufficient amount of DNA available, it may not
float to the top of the solution in a form that can be easily spooled or removed from the tube. However, the DNA will still be visible as white/clear
clusters by gently stirring the solution and pushing the clusters around the top. Post–Lab Questions What is the texture and consistency of the DNA
DNA is viscous and greasy. Why did we use a salt in the extraction solution High salt makes DNA less soluble in water. In order to dissolve, the
water needs to interact with the DNA. Since DNA is quite large, it needs to interact with lots of water for this purpose. When you add salt, the water
preferentially interacts with the salt (its small, and can move around in solution easier than the DNA can). This makes it so there is less water
available to interact with the DNA and it becomes less soluble. Is the DNA soluble in the aqueous solution oralcohol DNA is less soluble in an alcohol
such as isopropanol than it is in water. This is because alcohols are non–polar, whereas water is polar. The polar

DNA Profiling Essay example
From cases such as OJ Simpson to Chandra Levy, DNA profiling also called DNA fingerprinting or DNA typing has played a major role in the
criminal justice system. The law enforcement community uses DNA profiling to rule out or identify suspects. Unlike hair microscopy, bite mark
comparisons, shoe print comparisons, and firearm tool mark analysis, DNA typing has been developed through massive scientific research and has
undergone meticulous scientific evaluation (Innocence Project). DNA is a foolproof method of identifying a perpetrator of a crime.
Like fingerprints, DNA is unique, with the exception of identical twins; no two people have the same DNA. DNA profiling is a technique that can
identify the person responsible of a violent...show more content...
With over three million base pairs in the human gene, forensic scientists are able to distinguish a person's genetic makeup.
. DNA profiling was first introduced to the criminal justice field in the mid–1980's (DNA Initiative). DNA profiling was first described in 1984 by Alec
Jeffreys, a geneticist at the University of Leicester in Britain (Aronson, 7). Dr. Jeffreys found that the genes that have no function, called "junk DNA"
is where most of the variation is used for DNA profiling (Aronson 9). This region contains DNA sequences that repeat over and over again. Alec
Jeffreys determined that the number of repeated sections at different locations vary from individual to individual (DNA Initiative). Consequently these
repetitive regions became known as "variable number of tandem repeats" or VNTR's.
RFLP or restriction fragment length polymorphisms became the first scientifically accepted DNA analysis method in the United States (Jones). The
repeat segments are cut out of the DNA strand by a restrictive enzyme that acts like scissors and the resulting fragments are sorted out by
electrophoresis (Saferstein 391). However, there are some drawbacks using the RFLP method in the forensic science community. The RFLP technique
requires a large amount of DNA and must be of high quality and cannot be degraded (Jones). Forensic scientists and the law enforcement community

DNA Essay
DNA
Deoxyribonucleic acid and ribonucleic acid are two chemical substances involved in transmitting genetic information from parent to offspring. It was
known early into the 20th century that chromosomes, the genetic material of cells, contained
DNA. In 1944, Oswald T. Avery, Colin M. MacLeod, and Maclyn McCarty concluded that DNA was the basic genetic component of chromosomes.
Later, RNA would be proven to regulate protein synthesis. (Miller, 139)
DNA is the genetic material found in most viruses and in all cellular organisms.
Some viruses do not have DNA, but contain RNA instead. Depending on the organism, most DNA is found within a singlechromosome like bacteria, or
in several chromosomes like most other living things. (Heath, 110)...show more content...
(Grolier Encyclopedia, 1992)
DNA does not act directly in the process of protein synthesis because it does not leave the nucleus, so a special ribonucleic acid is used as a messenger
(mRNA). The mRNA carries the genetic information from the DNA in the nucleus out to the ribosomes in the cytoplasm during transcription. (Miller,
76)
This leads to the topic of replication. When DNA replicates, the two strands of the double helix separate from one another. While the strands separate,
each nitrogenous base on each strand attracts it's own complement, which as mentioned earlier, attaches with hydrogen bonds. As the bases are bonded
an enzyme called
DNA polymerase combines the phosphate of one nucleotide to the deoxyribose of the opposite nucleotide.
This forms a new polynucleotide chain. The new DNA strand stays attached to the old one through the hydrogen bonds, and together they form a new
DNA double helix molecule. (Heath, 119) (Miller, 144–145)
As mentioned before, DNA molecules are involved in a process called protein synthesis. Without RNA, this process could not be completed. RNA
is the genetic material of some viruses. RNA molecules are like DNA. They have a long chain of macromolecules made up of nucleotides. Each
RNA nucleotide is also made up of three basic parts. There is a sugar called ribose, and at one end of the sugar is the phosphate group, and at the

other end is one of several nitrogenous bases.
There are four main nitrogenous bases found in

DNA Forensic Essay
Setting aside the fact that DNA forensic technique is to a great degree helpful. This nonetheless, does not take away from the fact that even it too has its
limitation. In some multiplex situations such as (such as with DNA mixtures). DNA call for and depend on analyst putting together a variation of
subjective judgements that are prone to bias. Furthermore, contrary to the perspective that DNA is objective, some have suggested that DNA
examination interpretations might be biased and could even be impacted by various factors.
To illustrate the subjectivity of DNA forensic a study was carried out by Itiel E. Dror and Greg Hampikian. The study entailed taking DNA from a real
crime scene in Georgia that involved a Kerry Robinson who was indicted and then sentenced to prison for rape. As a part of his trial process a DNA
test was carried out on him and it was found that he could not be excluded. Resuming to the study, a mixed sample of DNA evidence was given to 17
expert analysts who were asked to interpret the DNA sample. In the end their findings were inconsistence, with only one of them findings matching the
judgement that...show more content...
The Deficiencies in forensic science have acutely distressing results, and the quantity of exonerations discussed earlier has highlighted the very real
danger that innocent people can be convicted. The reality of wrongful convictions has ascended to the forefront of public awareness on account of the
work of the Innocence Project and other organizations. The underlying factors that has contributed to the deficiencies in forensic science are the
following: unqualified analysts, contaminated evidence, misrepresented or exaggerated results, misinterpretation of results, absence of research for
basic assumptions and not following scientific protocol. (RR

Dna And Sequence Of Dna Essay
DNA (deoxyribonucleic acid) is a self–replicating nucleic acid that carries the genetic information in cells in a double helix structure. The 2 stranded
helix is composed of 4 nucleotides, Adenine (A), Thymine (T), Guanine (G), and Cytosine (C). The base pairs only form between A and T connected
by 2 Hydrogen bonds and G and C connected by 3 hydrogen bonds. Foremost DNA wrapping comes about as DNA wraps around protein called
histones. These combined loops of DNA and protein are called nucleosomes and the nucleosomes are packaged into a thread called chromatin.
Chromosomes are made up of packaged chromatin and can be seen in the nucleus of dividing cells and form around DNA replication. Furthermore,
DNA replication begins with 2 DNA strands being separated by the helicase enzyme. Single stranded DNA binding proteins attach to these strands to
keep them from re–connecting. 1 DNA strand begins to encode called the leading strand, which Forms from 5' to 3' end using DNA polymerase 3
the primary polymerase. The other strand is referred to as the lagging strand, which presents problems because it has to form from the 5' to 3'end as
well. As continuous replication of the leading strand continues the lagging strand forms in pieces called Okazaki fragments. RNA primase forms as
RNA primer and polymerase III lay down new DNA. This process repeats again and again. DNA polymerase I replaces RNA primers with DNA and
DNA ligase links the Okazaki fragments. Along with the process of DNA

Dna Discovery Essay

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