Genetics Essay, Research Paper

Over the past several years Genetics has become a leading link to understanding

how our body works. By mapping out deoxyribonucleic acid, or DNA, scientists plan to

find cures for various diseases, develop better, more efficient drugs, grow new organs,

evaluate environment hazards, and eventually build a human being.

Inside of every single cell in our bodies there are 46 chromosomes that are made

up of DNA. Half of your chromosomes are inherited from each parent, DNA is strung

along the chromosomes. DNA is the living instructional manual found in all living

organisms. The building block letters of DNA are Adenine, (A), Thymine, (T), Cytosine,

(C), and Guanine, (G). These are repeated over and over again about 3 billion times in our

body alone. DNA can be subdivided into genes, with each gene carrying the information

on how to produce a unique protein. Each gene consists of three of the building blocks

placed together. Along the stretches of DNA, genes tend to occur in clusters, like cities

separated by vast emptiness. When the DNA is collected all together you have a genome.

In the past scientists believed that there was more than 100,000 genes in the

human genome, but recent studies by Celera Genomics and many other scientist based

teams, have found that the number of genes to be 35,000. (Article #1) This new found

information has made some biologists ecstatic and has wounded the pride of others.

There are many people who are bothered by the fact that they don t seem to have (many)

more than twice as many genes as a fruit fly, said Eric Lander, director of the Whitehead

Institute Center for Genome Research. It seems to be some kind of affront to human

dignity. The 30,000 genes in our body compared to the 13,600 in the fruit fly does seem

to raise questions about why we have the abilities to do so much more when we don t

have that many more genes in our genome. Even though all creatures share the same DNA

code, some people still believe that there is a step-change between the rest of nature and

humans that separates us from them.

The Human Genome Project, starting in the 1980 s, is a research program

designed to construct a detailed genetic and physical map of the human genome,

determine the complete sequence of human DNA, localize 30,000 to 35,000 genes, and

perform similar analysis on the genomes of several other organisms.

Every species has its own genome. Every individual animal within a species has its

very own specific genome. Unless you are an identical twin your genome is different from

everyone on earth – and from everyone who has ever lived. Even though you have your

own distinct genome, it is still recognizable as a human genome.

Analyzing the human genome will give us insights into why people like the foods

they do, why certain people die of heart disease and others of cancer, and why some

people are outgoing and others are paralyzed by shyness. We will also be able to know

what body shape your children will have, the number of calories they are able to burn off

in rest, and the types of sports they will excel at and enjoy. Studying the genome can

related to a number of things, you can study the whole genome, or only a small part. You

can study the sequence, or function of a specific gene.

We are able to observe what happens when something goes wrong with a gene,

and how it affects our life and body. Certain diseases are cause by mutations in a particular

gene such as Blindness, cancers, bowl disorders, Leprosy, arthritis, Turner s syndrome,

Down Syndrome, and many other types of diseases. These genetic diseases are caused by

changes (mutations) in the DNA sequence of a gene or a set of genes. This can happen at

any given time, from when we are a single cell to when we are close to 100 or older. Some

scientists believe that there are specific disorders genes that cause the disease, but it is a

mutation that causes the normal genes to operate improperly. So to clarify all the mishap it

is better to say that there are mutated genes that cause genetic disorders.

In some diseases such as Down Syndrome and Turner s Syndrome, entire

chromosomes, or large segments of them, are missing, duplicated, or otherwise altered.

Single-Gene disorders result when a mutation causes the product of a single gene

to be altered or missing. Sickle-cell Anemia is an example of this type of disorder.

Mutations in the beta-globin gene cause the blood cells to become distorted and take on a

sickle shape. This makes traveling through the blood vessels hard and they begin to clog in

the narrow passages, causing various problems within the body depending on where the

clog is at.

Multifactorial disorders result from mutations in multiple genes, often coupled with

environmental causes. The complicated bases of these diseases make them strenuous to

study and treat. Some examples of this type of disorder are heart disorders, diabetes, and

cancers. Certain kinds of thyroid cancers are accumulated by malfunctioning genes, such

as Familial papillary thyroid cancer, and Medullary thyroid cancer (Article #5). Cancer is

caused by certain changes in our DNA sequence. But cancer is not developed by one

mutated gene, its the accumulation of many defected genes. This can happen through

inheritance of mutations or addition of new mutations during the life span of an organism.

Additions of new mutations can come from exposure to the sun, UV rays, infection by

certain viruses, spontaneous mutations and changes in copying the DNA during the aging

process. The genetic basis of cancer is possible by the cancerous cell dividing at

inappropriate times. This could mean that the cells either do not receive the signal to stop

dividing or they do not require outside signals to start dividing, so they divide when they

feel like it. When cancerous cells come in contact with other neighboring cells they do not

stop dividing like normal cells do, but they pile up and form a tumor. Cancerous cells also

have the ability to invade healthy tissue, leading to the spread of cancer throughout the

body.

Scientists were able to pin down the exact gene that is responsible for prompting

people s internal wake-up alarms. A mutation in this gene can cause the person to wake

up at very inappropriate times and causes them to become tried in the middle of the

afternoon. The mutation was found in the human Per2 gene on Chromosome 2. This is

common to many people the statistics show 1 in every 10,000 all the way up to 1 in every

100,000 people. There are a large quantity of people that don t realize that it is a disorder

so they never come in for treatment (Article #3)

Colourblindness is another of the many generic disorders. It is found in the X

chromosomes which is passed down from the female, never the male. If a woman with the

gene that entitles Colourblindness has a girl, the X chromosome of the baby will cancel

out the colourblind chromosome (X) a majority of the time. There is a slim chance that

when the X chromosome of the baby is weak the colourblind X will prevail and the girl

will be born colourblind. Females are the only carriers of this generic trait, very rarely does

a female get the trait. If that same woman were to have a boy, the X chromosome will

predominate the Y chromosome and the boy will indefinitely be colourblind. The ratios of

this disease are very different for men and women, 1 in 12 for men, and 1 in 250 for

women. Inherited genetic mutations arise about twice as often in men as in women

(Article #6)

Scientists have found that a retinal gene appears to be responsible for at least some

of the cases of macular degeneration, or blindness. The gene, which plays a role in the

metabolization of a fatty acid called DHA, has become defective and does not perform its

assignment accordingly. This suggests that people with the defected genes may have

trouble using the fatty acid in normal cell mechanisms. This leads to the deterioration of

the macula, a central part of the retina responsible for sharp, central vision. The loss of this

vision limits what a person can do, such as driving which is no longer acceptable, they

have trouble reading, and they lose all peripheral vision. This defective gene is past down

from generation to generation. To help cut back on the problems that can be caused by

eating foods that are high in DHA, such as salmon, shellfish, eggs, tuna, liver, and many

more (Article #2)

The entire genetic sequence of the disease labeled Leprosy has been deciphered.

This shows that with genetic sequencing of different organisms, such as the Leprosy

Bacterium, is extremely helpful in finding new, efficient treatments and drugs. In the case

of Leprosy it also help scientists to calculate how to grow the bacterium in a laboratory

which was impossible up to now (Article #8).

Ankylosing Spondylitus, or spinal arthritis is also formed from gene mutation. The

gene attacks the spine making it rigid as a poker, the extreme case, to just not allowing to

move easily, the moderate case. With learning how the gene is able to make this happen

we will be able to treat this, and maybe even cure it (Article #7).

Other disorders are not caused by malfunctioning genes or abnormal

chromosomes, but certain viruses can infect a gene and that gene will multiply with that

infections written in it. AIDS is a worthy example of this type of disorder or disease.

AIDS is cause by an infection with the HIV virus. The HIV virus infects an organism

incorporating its own DNA into the chromosomes of the infected cell. When this cell

divides, the viral DNA is inherited by all the daughter cells of the infected cell. So in a way

the infected cell now has a genetic disorder, caused by the introduction of a new DNA into

its chromosomes. The viral DNA will not transfer onto the next generation because the

sperm and egg cells of the organism are not daughters of the infected cell.

Scientists have recently been able to manipulate a skin cell to turn into heart tissue.

This can be radically helpful in the production of islet cells that produce insulin needed for

diabetes. The scientists turned the clock back on the skin cells to produce stem cells,

which have the ability to develop into any desired type of cell, from nerve to liver to

muscle. Then they manipulate the stem cell to become a heart tissue. This could be a

breakthrough for diabetic people, eliminating the daily insulin shots, and making live just a

little it easier (Article #18).

Tests with possible cures are been research continually, such as with tobacco

plants that contain a human gene. The gene interleukin10 can be massed produced to help

treat bowl disorders. Using genes from other living organisms are growing more common

in science (Article #4).

To stop the wide shortage of organ transplants needed, scientists have started

researching humanized pig organs. The birth of a litter of genetically modified pigs have

started this research. Each of the pigs has a marker gene introduced into its genetic

code. This produces a knock-out pig, where scientists will knock out the gene that leads

to the human immune system. This will eliminate the rejection of the pig s organs when

placed in the human body. The process is called Xenotransplants, and it could start in as

little as 4 years (Article #19)

In the same sense scientists have been able to turn a plant s leaves into petals,

allowing nurseries to produce plants that bear flowers where leaves were. This is possible

by five genes that are manipulated, either by traditional breeding, or by genetic

engineering. Breeders will be able to make colourful double flowers in which stamens and

leaves grow into petals and enhance the fragrance. This not only could help the nurseries

but the drug industry as well, by allowing them to grow greater quantities of therapeutic

chemicals that come from flowers (Article #17).

Additional traits can be discovered by sequencing the genes. Not only will

scientists be able to see whether or not you have a fatal disease, but they will be able to

envision what type of body type your child will have, what kind food they will have a taste

for and whether they will be outgoing or paralyzed with fear about leaving the house.

There are innumerable amount of traits that we will be able to see when we look at a

persons genes. What kind of sports they will like, whether they will be overweight or

underweight, how many calories they burn at rest, and whether they are a psychopathic

killer (Article #9). We will be able to know ahead of time what kind of lives our children

will lead, in some ways this is a good thing because it will prepare us for what type of

parenting we have to do. But in other ways if we find out what likes and dislike our child

will have we will have the choice, if we want this child or not, this exact thought raises

many questions about the morality of genetic sequencing.

Scientists have just encountered the gene that controls the height of humans also

governs life and death, meaning that short people are genetically programmed to live

longer than tall people. Using Nematobe C.Elegan, worm-like creatures, scientists

eliminated these genes and the result is either mutant giant, or dwarf worms. They

discovered that the genes that were knock out which produce growth hormones, also

influence life expectancy. The lower levels of growth hormones, the longer the life

expectancy. Even though it was only tested on C. Elegans, human have the same

insulin-based growth system, so it applied to humans as well (Articles #20,25).

A discovery has been made that there is a gene that explains why moderate

drinking can prevent heart attacks. This gene, or variants of it, makes the body break

down alcohol very slowly which raises the levels of heart-protecting good cholesterol in

the blood. Drinkers with this gene were found to have a sharply lower risks of heart

attacks than those that dispense alcohol at a faster rate. The gene produces enzymes called

alcohol dehydrogenase that breaks down alcohol. The gene either breaks down the alcohol

quickly or slowly. You inherit one of the genes from each parent, so you can have two fast

genes, two slow genes, or one of each. Those who have two slow genes and average one

drink a day have a 85% less risk of a heart attack than those who have two fast genes and

hardly drink. With conditions such as obesity, overdose of alcohol, smoking, and a history

of heart illness the risk was still 35% lower (Article #16).

Jurrassic Park the movie directed by Steve Speilberg, based on a book by Michael

Crichton, has raised many questions about the correctness of taking DNA found in fossils

and decoding it. Geologists right now are extracting the DNA from prehistoric bugs

stomach. If the chance that the DNA turns out to be belonging to a dinosaur they want to

decoded it and possibly clone a dinosaur. Cloning is made from a single adult cell joined

with an egg cell, the genes of which have been removed, so all the geologists need from

the DNA of a dinosaur is the adult cell, and an egg cell. If the geologists decide not to

clone the dinosaurs then they will use the DNA to find out a little more about dinosaurs

and the environment in which they lived (Article #10).

Apart from just studying the DNA and sequencing the genes, the knowledge of the

DNA can be used in fighting crimes. Any type of body fluid and cells can be used to find

out who was present at the scene of a crime. Evidence such as sperm, blood, pubic hair,

skin cells, and saliva can be taken into a lab and studied to find out who exactly it belongs

to. This is accomplished by searching a computer from a DNA Databank. A DNA

Databank keeps records on the DNA of everyone they possibly can, for use in such

situations as a crime scene investigation. Once the investigators have a list of possible

people that are suspected, they now go and get a swabbing of the inside of their mouths

for further testing. People have rejected this, calling it an invasion of privacy. They believe

that if employers were to be able to have access to the DNA Databank they would know

all about their employee including diseases or disorders, characteristics and traits. Meaning

that if your employers looks at your DNA and finds that you have a history of heart

disease in your genes and they believe that you are not fit for the job they can fire you on

that account. This is a downfall of keeping DNA files on hand, they can be used against

people, not just to help them (Articles #11,12,13,14,15)

Scientists have not just been mapping the code of human and animals, but of plants

as well. They have been able to genetically modify plants to help them survive longer and

produce better food, flowers, or fragrance depending on what they want enhanced.

Genetically Modified foods have become more common in recent years. It was mostly

grains that have been engineered with genes from non-grain species that make the plants

resist insects or tolerate pesticides. So a farmer can spray his crops with a pesticide and

have it kill everything in its field except his harvest. There are some problems with this,

such as allergies in humans. Scientists have yet to figure out whether or not people can

develop allergies towards GMOs, but some people don t want to take the chance. The

pesticide resistant plants could jump to wild plants, creating super-weeds or could harm

valuable insects by making their food unfit to eat, such as the Monarch butterfly. The

Genetically Modified Atlantic and Pacific salmon are growing faster than normal salmon, if

the super-salmon were to escape from the production plantations, they could mate with

normal salmon and corrupt their whole genetic pool. There is also problems with patent

genetically modified plants, if a person suspects that his neighbor was stealing his

super-seeds, the only way to prove he s not is to spray his field. If the crop dies then he is

not stealing the crops, but he lost all that years harvest. If the crop lives, then the company

can sue the neighbor. So you can see that there is a number of problems that could arise

with releasing the GMOs. Some Health officials don t agree with Genetically Modified

foods, claiming that it is unhealthy and dangerous to humans and the environment, if not

properly controlled. Right now in Canada they are looking for better ways to control

GMOs and the sale of them. Officials believe that their will be a lot of problems with

GMOs and how people will react to them being on the shelf, they think that there will be

destruction of fields and food products just like the reaction in Europe last year.

(Articles #21,22,24)

After figuring out the genome of humans there is still Protenome, a complete

listing of the 250,000 or so proteins that the 35,000 genes are capable of making. Proteins

can vary in health and disease, and the long chains of amino acids do not string out but

curl up on themselves in complex 3D shapes, making it indefinitely harder to break the

code. Most of biology happens at the protein level, not the DNA level, Dr. Craig Venter

of Celera Genomics points out. Scientists not only have to figure out what the listing of

proteins is but how they change in disease and how they fold. This is dubbed the Greatest

unsolved problem in biology. (Article #27)

As you can see there is still a long way to go in finding out everything there is to

know about Genetics. But when we do find out everything about Genetics and the human

body, there is nothing left to the imagination, and a part of that will be sorely missed.

Bibliography:

1) Scientists read book of life , find it shorter than expected by: Malcolm Ritter February 12

2) Study finds gene linked to cause of blindness by: Andy Ogle February 2

3) Gene linked to wake-up by: Greg Lavine March 2

4) Vatican concerned over gene transplant into crops February 9

5) Dear Doctor by: Paul Donohue February 16

6) Dear Doctor by: Paul Donohue February 8

7) Dear Doctor by: Paul Donohue March 27

8) Leprosy gene code may aid treatment of malady February 26

9) Chip off old block not set in stone by: Jill Barker March 8

10) Fossil find reminder of Jurassic plot by: Jamal Halaby February 8

11) Jury hears DNA details by: Ellen van Wageningen April 19

12) DNA search yields suspect by: Ellen van Wageningen April 12

13) Guilty plea for man nabbed with DNA February 20

14) B.C man challenges new national DNA databank February 6

15) Hanratty s body exhumed for DNA testing in murder February 6

16) Gene helps alcohol boost heart health by: Linda Johnson February 22

17) Gene scientists turn leaves into flowers February 6

18) Skin cells turned into heart tissue by: Roger Highfield February 24

19) Human pig clones may be a reality in four years April 21

20) Longevity theory gets short shrift by: Bev Wake March 10

21) Panel raps biotech rules by: Tom Spears February 5

22) Health officials defend frankenfood practices February 6

23) Resistance to cloning futile, scientists say March 10

24) Spy Agency warns of bio-tech protests by: Jim Bonskill February 12

25) Genetics research gets a boost by: Allan Swift March 1

26) DNA mapping project links diabetic girl, MD by: Veronique Mandel February 13

27) Human mystery by: Nigel Hawkes February 17