DNA research paper.

Ben Hartman Grant Corrigan Mia Fernandez

A brief history of DNA and a crucial scientist.

DNA is found in every living thing, from humans to microorganisms. Without DNA, we

would all have the same characteristics. The study of DNA was started by a man named

Gregor Mendel, in 1900

This discovery was re-discovered by Dr. Barbara McClintock, a geneticist born in 1902.

In the study of genetics, they used ornamental corn to help

them discover how chromosomes carry specific genes to new generations. At Cornell

University in the late 1920’s to early 1930’s, the genetics department brought in

ornamental corn to study. Dr. McClintock started working on identifying and labeling

the 10 chromosomes of the corn. She was able to see the parts of the corn

chromosomes by using new microscopic techniques. She spent many years researching

and finally came to a conclusion much different than the popular belief. She discovered

that genes don’t in fact, stay in one place. They move. She called them “jumping

genes”. She believes that these “jumping genes” caused different appearances in

plant’s offspring by either activating or inactivating the gene that controls the color of

the kernels. Dr. McClintock observed two different kinds of transpositions, which are

dissociaters and activators. The dissociaters can “jump” to a different place when

signaled by activators. She concluded that the dissociaters would cause changes and

the nearby genes of the chromosome and the color of the kernels in the ornamental

corn. She verified this conclusion from multiple and repeated experiments. In 1951, Dr.

Barbara McClintock showed her discover to nine groups of scientists from all around the

world at a scientific meeting. Her discovery was not well accepted; the other scientists

were not as amazed as she was and they thought her methods were old fashioned. The

other scientists were using other technologies, such as the electron microscope.

Although her methods were out of date, her discovery was ground-breaking.

Her discovery wasn’t really believed

until the 1970s, when a group of molecular biologists found bits of DNA jumping around

in bacteria. Later, scientist found these transpositions in other things besides corn.

They have discovered that every living thing has transpositions. This finally confirmed

that Dr. McClintock’s theory was right all along.

The modern manipulation of DNA.

Ever since the discovery of DNA and genes, the manipulation of them has been a

somewhat controversial subject. The technology used in genetic engineering is called

DNA Technology. This technology can be used to cure diseases, to treat genetic

disorders, for the improvement of food crops and much more. Genetic Engineers use

two main parts of the DNA strand to manipulate genes how they want which are called

restriction enzymes and cloning vectors

The Restriction Enzymes are used to cut DNA strands into smaller parts which make it

easier for genetic engineers to work with. These restriction enzymes cut the DNA chains

separately between the G nucleotides and the A nucleotides, therefore creating single

chains of DNA. These “tails” are called sticky ends. The sticky ends can bind together

with others so that essentially, two different parts of two different DNA strands can bind

together making an entirely new strand.

After work with restriction enzymes, specific genes can become isolated but cloning

vectors must be used to place the new isolated genes and the new strands previously

combined into an organism. The cloning vector is basically a vessel that is used for the

transportation and cloning from one organism to another. Plasmids, rings of DNA found

in bacteria contain cloning vectors. To use one of these cloning vectors, it has to be

removed from the gene itself. Once the cloning vector is isolated, the plasmid is then

cut, removing the unwanted gene. Once the unwanted gene is removed, the “donor

gene” or the new gene is added.

This remarkable simple process can produce many good things for mankind. It can help

to prevent diseases and in some cases, cure them. Although this process can cause a log

of good and fix many problems, some people believe that this is dangerous and almost

tampering with the fabric of life itself.

Before this type of genetic engineering, things were created only by nature, which to

some is ideal. Others feel that genetic engineering is a great milestone for science and

opens up many new possibilities.

Genetic engineering has opened up many possibilities in agriculture and farming alone.

Previously, plants and other types of grown foods were at the mercy of their

environments and the types of infestations or diseases that could hurt them. With

genetic engineering they can make “Franken-foods” that can be resistant to these

forces, where without them they would normally die.

How DNA works briefly.

DNA molecules consist of tub long chains each. The chains that DNA is

made up of is nucleotides. Nucleotides are made up of three different parts:

those three parts are- sugar molecule, and that is called deoxyribose. The

other is a phosphouris atom and that is surrounded by oxygen atoms; and a

molecule that is referred to as an nitrogen- containing base because it

contains a nitrogen atom.

All DNA molecules have an identical sugar base molecule in them that is

called deoxyribose sugar phosphate. Nitrogen molecules contain base,

however can be one of four kinds, first is called adenine (A), second is called

guanine (G), third is called cytosine ©, and last is called thymine (T).

The double helix was discovered by James Watson, and Francis Crick in

1953. They suggested that if they made a model of DNA structure. The

model proposed was that DNA is composed of two nucleotide chains that

wrap around each other to form a double spiral. This “double spiral” shape

is now called a Double Helix.

Adenine and guanine combined are called purines. The adenine is made up

of NH2, HC, N, NH, C4, and C. Thymine and cytosine combined are called

pyrimidines. Bases just like the two listed above commonly have two rings

of carbon and nitrogen atoms. Such as adenine and guanine are called

purines. Bases that have one ring of carbon and nitrogen atoms such as

adenine and guanine are called pyrimidines.

RNA is like DNA; it is an nucleic acid made up of repeating nucleotides. The

difference between DNA and RNA is that RNA's sugar molecules are ribose,

where as DNA's sugar molecules are just deoxribose sugar. A rare part that

is in RNA uracil, that is a nitrogen thymine.

There are three different types of RNA, and those three types are called

messenger RNA (mRNA), the second is called transfer RNA (tRNA), and the

last one is called ribismoal RNA (rRNA). There are about 45 variations of

(tRNA).