DNA Day Middle School Essay Contest Winners
Question 1: Why is it important for us to discover the patterns of genotypic and phenotypic similarity and difference in living things and
why should we understand the theories that describe the importance of genetic diversity for species and ecosystems?
Preethi Padmanaban (8)
Chaboya Middle School
It was the September of 1845. Farmers in Ireland were happy with their abundant potato crop. As harvesting time approached, uneasy farmers noticed the leaves of their potato plants curling and turning a deathly black and the tubers rotting to a black mush. That year, one million Irish people died of malnutrition,
cholera, and typhus brought about by eating the decayed vegetables in what was later known as the Irish Potato Famine.
So what exactly occurred to turn a seemingly healthy crop into inedible mush? Phytophthora infestans, a fungus originally transported from ships sailing from North America, had spread its airborne spores throughout Ireland and neighboring European countries. In Ireland, potatoes had barely any genetic variety. As
a result, when the fungus attacked, the potatoes all succumbed to the disease. Now, farmers grow crops with genetic diversity, so that if and when a fungus strikes, at least some of the crops would have a gene that would provide immunity against it.
As this scenario delineates, genetic diversity at the species level is tremendously vital for natural selection, as it enables crops to adapt to changing factors in their environment, such as new diseases, pests, and climates. During the process of natural selection (overproduction, competition, selection, and
reproduction), only organisms with favorable characteristics manage to survive and reproduce in their environment. Therefore, in the end, all of the organisms in that population have the favorable trait and are able to flourish.
Genetic diversity at the environmental level is also extremely important. A recent study has shown that more genetic diversity of leaves decomposing in a forest increases the amount of carbon and nitrogen released into the soil. This shows that when the genetic biodiversity decreases, it affects the ecosystem.
The diversity also matters to preserve an endangered population.
The genotype of an organism is its genetic construction, or the sets of genes an organism carries and mostly influences its phenotype. The organism’s phenotypes include its development, behavior, appearance, and other observable factors. During Gregor Mendel’s extensive genotypic and phenotypic research, he found
that when two different alleles are present in the genotype of an organism, the dominant feature is observed in its phenotype. The brown eye color is a prevalent phenotype, coded by a dominant gene. Along with the genotype, the environment that the organism lives in also affects its phenotype. For example, the
pink or white color phenotype of flamingos is made by the food they eat.
Punnett squares are diagrams that are used by biologists to determine the probability of an offspring having a particular genotype. They show all of the different possibilities of dominant and recessive alleles of a trait that the offspring can have. However, genotypes can also be synthetically altered. For
example, bananas are very susceptible to Black Sigatoka, a destructive disease. Scientists have isolated the disease-resisting gene of one crop and implanted it into another crop that had desirable traits, such as sweetness. As a result, new genetically altered disease-resistant, sweeter bananas have been grown.
Common methods of identifying genotypic patterns are by single nucleic polymorphism or SNP analysis, hybridization, and DNA sequencing. SNP uses the method of comparing DNA strands from different organisms to a reference DNA strand to find a single different base (A, T, G, or C). Hybridization uses the principle
of binding complementary strands together (Adenine and Thymine, Guanine and Cytosine) to find out the exact order of the nucleotides in a strand of DNA. DNA sequencing also determines the order of the bases in an organism’s DNA. Human genotyping plays an important role in identifying many diseases and developing
drugs. Phenotypes are studied by phenotype mapping that maps a set of genotypes, the physical region of the chromosome, to a set of phenotypic features.
In conclusion, genetic diversity is important both at the species level and at the ecosystem level. After all, diversity is what sets us apart from each other! It plays a significant role in the survival of populations and ecosystems. Therefore, we must strive to protect our ecosystems with the knowledge of the
importance of diversity that we have. As scientist Mark Hunter, associate professor of ecology, UGA, says, "This research is especially important in the current mass extinction period. Plants capture the energy that drives the planet. By continuing to destroy plant habitats, we reduce the available gene pool. In
the end it could harm the biggest ecosystem of all: planet Earth."
1. Bagley, M.J., S.E. Franson, S.A. Christ, E.R. Waits, G.P. Toth. 2002. Genetic Diversity as an Indicator of Ecosystem Condition and Sustainability: Utility for Regional Assessments of Stream Condition in the Eastern United States. U.S. Environmental Protection Agency, Cincinnati, OH.
2. Powledge, Fred. "The Irish Potato Famine." About Biodiversity. 26 Jan. 2004. Bay and Paul Foundations. 28 Dec. 2007 .
3. "genetic drift." Encyclopędia Britannica. 2007. Encyclopędia Britannica Online. 28 Dec. 2007 .
4. Hawtin, Goeffrey C. "Genetic Diversity and Food Security." Courier. 9 Feb. 2008 .
5. "Intraspecies Diversity Helps Ecosystems, Study Says." National Geographic. 21 Aug. 2002. 9 Feb. 2008 .
6. "Genotype versus Phenotype." Understanding Evolution. 2006. University of California Museum of Paleontology. 8 Mar. 2008 .
7. "Genotype-phenotype distinction." Wikipedia 8 Mar. 2008 .
Felix Wangmang (8)
Robinson Middle School
The universal nature of genes provides a foundation to understand life. Knowledge of genetics is important in many areas of science. For example, genetics helps explain the evolution
of species. When scientists study diseases, they consider genetics. The breeding of animals also relies heavily on genetics. Every living organism is the physical manifestation of an internal code of inheritable information. Phenotype, the expression of observable traits, is determined by genotype, the internal
blueprint written in genetic code, copied at the time of cell division or reproduction, and passed from one generation to the next.
All humans have the same basic genes, but some of these genes contain different sequences that make each person unique, such as types of blood and skin color. Some of the differences in the genes can cause illness. Scientists are working on identifying, treating and preventing hereditary diseases. Progress has
accelerated since the Human Genome Project (HGP) was completed in 2003 (“Human Genome,” 2007). Now, scientists at the National Institutes of Health are attempting to create a Cancer Genome Atlas to identify all the genes in cancer. A study recently completed at Johns Hopkins University identified 189 gene
mutations in breast cancer and colon cancer. Analysis of more than 13,000 genes from tumors showed that each type of cancer had about 100 different genes with mutations (Oren, 2007). One of the identified tumor suppressor genes is known as p53. Functioning normally, the p53 protein binds with DNA and stimulates
another gene to produce a different protein called p21, which stops cell division. If p53 is damaged, not all the remaining steps in the process can occur and p21 is not produced to stop cell division (Oren, 2007).
Diversity is a defining characteristic of individuals, species, and ecosystems. Charles Darwin’s theory of evolution by natural selection was written in 1859 and extolled diversity (Fletcher, 1995). Genetic diversity is nature’s way of ensuring the survival of a species. Having a broad range of unique
characteristics allows plants and animals to live in changing conditions. Humans can benefit from crops that grow well in harsh climates as well as these that thrive only under moderate conditions. A study conducted by the National Science Foundation found that genetic diversity and biodiversity are dependent up
each other, and it has been estimated that removal of one plant species can affect 30 other species, including insects, animals, and other plants (“Primary,” 2007). Additionally, humans depend on plants and wildlife; for example, penicillin is made from a fungus. At least a quarter of all prescriptions written
annually in the United States contains chemicals discovered in plants and animals (Sattelberg, 2006).
An ecosystem needs different kinds of plants and animals for optimal functioning, and the genetic diversity of species within a habitat affects ecosystem processes greatly. Gambusia georgei, a portion of the San Marcos river system, is an example of an ecosystem unbalanced by man. The main problems for all the
species come from increased pumping, elimination of habitat, and degradation of water quality caused by urban expansion. Researchers estimated that there were 1,000 unique species in 1969, 100 species in 1980, and only a few dozen in 1982 (“Taxonomy,” 1996). As a result, the San Marcos ecosystem is in a
precarious situation. For another example, San Antonio/Guadalupe River’s freshwater inflows are a huge threat to the whooping crane and could lead to its extinction. Without sufficient freshwater inflows, wildlife resources, including fishes, crabs, and shrimp, all decline. Data showed that crabs were the highest
in protein and nutrition for the whooping crane, but when crabs are not available, whooping cranes switch to other foods. But because of the poor nutritive value of these alternate foods, the whooping crane may actually burn up fat reserves and lose energy for periods of the winter (Stehn, 2001). So, if the crabs
become extinct, all of the species that rely on it for food will also suffer and may become threatened or endangered.
In recent years genetic research has made great progress. Within 20 years, many of today’s most devastating illnesses may be curable because of the increasing knowledge of genetics that benefits society daily. Due to the HGP and other projects, scientists are gaining more knowledge about the genotype of both
humans and other animals. With all this knowledge, scientists can introduce desirable genes to plant and animal breeders and work to prevent a variety of devastating diseases, moving toward healthier ecosystems.
Fletcher, S.R. (1995, May 16). Biological Diversity Treaty: Fact sheet. Retrieved February 9, 2008, from CRS Report for Congress web site: http://www.cnie.org/nle/crsreports/biodiversity/biodv-3.cfm
“Human Genome Project.” (2007). Retrieved March 4, 2008, from Human Genome Project Information Web site: http://www.ornl.gov/sci/techresources/Human_Genome/faq/faqs1.shtml
Oren, M. (2007, Feb. 21). Genetics & Cancer Risk. Retrieved February 9, 2008, from Your Total Health web site: http://yourtotalhealth.ivillage.com/genetics-cancer-risk.html
“Primary and Secondary Resources.” (2007). Retrieved February 24, 2008, from Protecting Endangered Species: In the shadow of the shuttle web site: http://www.turnerlearning.com/efts/species/
Sattlelberg, M. (2006, June 7). Endangered Species Act and Biosolids: Why Save Endangered Species. Retrieved February 29, 2008, from web site www.westminsterworkshop.com/Presentations/ESAbiosolidsRMS.ppt
Stehn, T. (2001, Nov. 26). Relationship between inflows, crabs, salinities, and whopping cranes. Retrieved February 24, 2008, from Whooping Crane web site: http://www.learner.org/jnorth/tm/crane/Stehn_CrabDocument.html
Taxonomy: Species: GAMBUSIA, San Marcos. (1996, Mar. 14). Retrieved February 9, 2008 from web site: http://fwie.fw.vt.edu/WWW/esis/lists/e252003.htm
Elizabeth Cole (7)
The greatest dream of Stephen Hawking, the renowned theoretical physicist and sufferer of the genetic disease Amyotrophic Lateral Sclerosis(ALS) is to go into space. While through
his theories he has metaphorically done just that, in his paralyzed state he may never physically be able to go into space.(9) Usually fatal, ALS is a genetic disorder caused by the deterioration of motor neurons, nerve cells in the central nervous system that control voluntary muscle movement. Hope exists for
the future: the discovery of a new gene that causes some forms of ALS will enable the development of new model systems to understand the disease and open the way for development of new treatments.(10)
Deoxyribonucleic acid(DNA) is a nucleic acid that contains the genetic instructions for the development and functioning of living organisms. The genotype is the genetic makeup, or genome of an organism. The phenotype is the observable physical characteristics of an organism as determined by the genome and
environmental influence. Genetic engineering, the alteration of an organism’s genetic material is used for selective breeding, hybridization, and recombinant DNA formation.(7) A form of artificial DNA, recombinant DNA is created through the combination or insertion of one or more DNA strands. Recombinant DNA and
selective breeding can be used for many applications.
Understanding the human genome can help human heath care professionals increase the quality of lives, prevent future diseases, and reduce medical costs. Gene therapy will be able to treat and prevent the four-thousand diseases in humans and animals caused by dysfunctional genes.(5) If a gene is altered so that
the encoded protein cannot carry out their normal functions, genetic disorders result like cancer, autism, heart disease, amyotrophic lateral sclerosis(ALS), diabetes, and color blindness.(5) Though some genetic disorders such as cancer are traced to genetic abnormalities acquired during life in a few cells, most
gene diseases are inherited from the parents and are present in all parts of the body. Gene therapy corrects dysfunctional genes by either fixing dysfunctional genes or replacing abnormal genes with normal genes.(4) Celera, Inc is using genetic discoveries to deliver disease management solutions.(1)
Mapping the microbial genome can assist in developing vaccines for antibiotic-resistant pathogens, such as the drug-resistant bacteria Staphylococcus aureus(S. aureus). If scientists study the bacteria’s genes, they can understand the correct genes needed to make vaccines prevent diseases. Through its Microbial
Genome Program(MGP), the US Department of Energy(DOE) Office of Science has sequenced more than 485 microbial genomes and 30 microbial communities having specialized biological capabilities.(8)
Geneticists can help clean up the earth by putting artificially bred microbes to work. Microbes could help us survive by cleaning up toxic waste sites, managing the atmosphere’s high carbon dioxide, detecting disease-causing organisms, and degrading toxic substances. Microbes could break down carbon dioxide into
harmless molecules. They could also manufacture and develop renewable energy sources people need like methane and hydrogen.(8)
Traditional breeding and genetic engineering can insert genes from one plant into another and create disease resistant, less costly, and increased nutritional value crops. From Ethiopia, a barley plant has provided genes that protect California’s $160 million barley crop from the lethal yellow dwarf virus. The
United States sugarcane industry was saved from a collapse by a gene from a wild Asian sugarcane species. Genes from an Indian species of wild rice protect Asian crops from four major rice diseases.(6) Rice is the predominant food in developing countries, and it provides twenty-seven percent of dietary energy
Scientists can help stop the extinction of animals through studying their genetic patterns and selectively breeding them. Because cheetahs are near extinction, each cheetah is closely related to each other and have almost no variety in their phenotype and genotype.(12) Organizations like the Hoedspruit Endangered
Species Center(HESC) and zoos are trying to stop cheetah extinction by breeding cheetahs and preventing inbreeding.(2)
Understanding and studying DNA barcodes and genetic information will give us more information about evolution. Philosophical issues concerning biodiversity, phylogenetic inference, and species inference are relevant to DNA barcoding. A DNA barcode refers to a short region of a gene which changes over evolutionary
time at a pace that results in calculable differences between species. The Consortium for the Barcode of Life has brought together museums and research organizations with the goal of producing DNA barcoding information for all species.(3)
Mapping the biodiversity of all organisms can help humans solve many problems. Genetic evolution is controversial but with bioethical diligence, maintaining genetic diversity and using applied genetics may help all species of the world including us survive!
(1)About Us. (May, 1998)
Web site: http://www.celera.com/celera/about
(2)Breeding programmes. (n.d.)
Web site: http://www.wildlifecentre.co.za/breeding.htm
(3)Biodiversity and DNA barcoding. (June, 2003)
Web site: http://plato.stanford.edu/entries/biodiversity/#BioDNABar
(4)Gene Therapy. (February, 2008)
Web site: http://www.ama-assn.org/ama/pub/category/2827.html
(5)Genetic disorder. (n.d.)
Web site: http://en.wikipedia.org/wiki/Genetic_disorder
(6)Genetic Diversity. Miller, K. and Tangley, L. (1991)
Web site: http://archive.wri.org/item_detail.cfm?id=2027§ion=ecosystems&page=pubs_content_text&z
(7)Genetic Engineering. (2007)
Web site: http://encarta.msn.com/encyclopedia_761557775/Genetic_Engineering.html
(8)Microbial Genomics. (January 29, 2008)
Web site: http://microbialgenomics.energy.gov/index.shtml
(9)My experience with ALS. (n.d.)
Web site: http://www.hawking.org.uk/disable/dindex.html
(10)New ALS Gene Paves the Way for Better Understanding,
New Treatments. Robinson, R. (February 28, 2008)
Web site: http://www.alsa.org/news/article.cfm?id=1225
(11)Nutritional contribution of rice and impact of biotechnology
and biodiversity in rice-consuming countries. Kennedy, G.,
Burlingame, B., and Nguyen, V. (n.d.)
Web site: http://www.fao.org/DOCREP/006/Y4751E/y4751e05.htm
(12)Why does the cheetah lack genetic diversity? (n.d.)
Web site: http://www.cheetah.org/?html=aboutcheetah-03
Question 2: Why is it important for us to learn about our family health history? What can our family health history tell us? What doesn't it tell us?
Jason Derby (7)
Cuba City Elementary School
A Family Health History is Very Important
Your family medical history is a record of illnesses and medical conditions affecting your family members. It provides insight into the diseases and conditions that are common to your family. Just as each of us inherits genes that determine our appearance, such as hair color and eye color, each of us also
inherits genes that may cause or increase our risk of certain medical conditions. Your family medical history includes information for each person about diseases, age of disease onset, causes of death, and other important health information.
This history can be used to give you clues about your risk of disease. Your doctor may use your family medical history to evaluate your risks, recommend changes in diet or other habits, determine what medical tests to order, and help identify a condition that might not otherwise be considered by your doctor. By
knowing your risk, you and your doctor can make informed decisions about prevention of certain diseases and early testing.
Many health problems are inherited. Heart disease, diabetes, asthma, osteoporosis, and certain cancers are just a few examples of health problems with a hereditary component. A family health history helps predict your risk for these conditions and can be used to prevent and reduce illness. Certain family health
patterns can help you and your doctor know what early warning signs of a certain illness to look for. For example, if your father suffered from high cholesterol and had a heart attack at age 42, it would probably be a good idea for you to start getting regular cholesterol checks when you are in your thirties.
This health information can guide you to good preventive health care, such as regular doctor check-ups, healthier eating habits, and exercise. Early diagnosis and treatment can cure or control many illnesses.
A family medical history has its limitations. It cannot tell a person that they will or will not get a certain disease. For example, having a family member with a particular disease suggests that you may have a higher chance of developing that disease than someone without that disease in their health history. It
does not mean that you will definitely get the disease. Genes are only one of many factors that contribute to disease. There are other factors, such as gender, race, age, environmental, and lifestyle habits, such as diet and physical activity, which contribute to many diseases.
A family medical history cannot predict your future health; it only provides information about risk. However, knowing that you’re at risk for certain diseases can help you take the appropriate action to keep you healthy.
Sarah Henderson (7)
Kepley Middle School
Why is it important to know your family health history? What can and can’t it tell us? Keep reading to find out. It's very important to know your family health history. A health
history includes what medical conditions exist, who had them at what age, and what the effect was on their life. Some diseases or conditions are hereditary and show up over many generations in a family. Also you can see which family members died or were affected in some way from these diseases. A few diseases
that will show up in a history are: cancers, cystic fibrosis, and diabetes.
If you have a complete family health history you can see the diseases that have shown up in your family. By knowing this you can start taking precautions to help protect yourself from those diseases. Even the diseases that have only shown up once or twice throughout time may potentially be passed on to you. This
may be because descendants were carriers without developing the condition themselves.
The knowledge of a complete family health history is beneficial but has its limitations. Your health is not only affected by heredity, but also by your environment and living habits. Take a look at this scenario. Identical twins were born and separated by adoption at birth. One lives in a clean, stable home with
a family that lives a healthy active lifestyle. The other lives in a home where a parent smokes, everyone eats junk food whenever they want, and their main activity is watching TV. The one that lives in the active, healthy home will likely have a different health record than the one who lives in the sedentary
home with a less favorable environment. Thus their environment and lifestyles have the potential to influence their health more than their health history. Where someone lives and what they do for a living can also influence their health. If one family has a clean health history, but gets their water from a
contaminated source, that environmental influence could negatively affect their health. If a family with a less favorable health history moves into a healthy environment they may positively influence their health. This may be influenced by the good, clean, healthy air that they are breathing or that the
environment is not full of chemicals that will effect their health.
Genetics play a major role in your family health history because they can tell you what you have a good chance of inheriting and what you don’t have a good chance of inheriting based on how often it has shown up over time. My maternal grandmother had breast cancer and died from it. She didn’t know that her aunt
and grandma had both had the same disease. Maybe if she would have known that bit of family health history she would have been more likely to be screened for the disease and found it sooner. If she had found the cancer sooner, there may have been a better chance to stop it and I could have known her. My paternal
grandmother has high blood pressure. This shows up in her family through multiple generations. Many of them have had serious problems related to the high blood pressure and have eventually died of strokes. As a consequence of this, my dad is carefully watching his blood pressure and taking medication.
There are genetic disorders that could severely limit a child’s quality and length of life such as Tay-Sachs disease. This disease causes problems with sight, hearing, and movement, eventually leading to seizures and typically death by age five. Parents who know that they are carriers of that gene may choose to
adopt rather than having their own children to avoid passing on the disease. Some think this is a good thing, others don’t think it is because of religious beliefs. Genetic counselors can help people make that choice.
This is why it's important to know your family health history and what it can and can't tell you. Now you can apply that knowledge and see what diseases and disorders you may or may not inherit, based on your family’s history. Keep in mind that your lifestyle and the environment around you also play a big role in
your health. Some families don’t want to talk about their health issues. They might be afraid of what they’ll find or just would rather not know. I believe knowing your family’s health history is a very important thing. I wish my grandma would have.
Mom and Dad - discussion of our family health history
Keenan Baker (8)
Owsley County High School
What would you say if I told you that you can predict if you are likely to get a disease, a disease transmitted through genes? You would probably think I was crazy… but think about
it. When you go to a new doctor why does he ask about diseases within your family for several generations, cultural history, and lifestyle choices? He wants to establish a family health history in order to determine the likelihood of you getting a disease like diabetes, heart disease, cancer and many more
diseases or conditions.
Knowing their family health history is especially important to women who are planning to have children. Women who have one or more family members who have given birth to a child with a birth defect are at a higher risk of having their own child with a birth defect. Because many birth defects are directly
connected to genetic mutations, women who have a family history of birth defects often have genetic testing in order to determine their likelihood of having children with birth defects. A child born with birth defects can result in great financial burden, mental, and emotional stress. Due to this, many women who
know they have an increased chance of giving birth to children with birth defects will opt to either adopt or not have children at all. (Romitti, 2007)
Sometimes just knowing your family history may not be enough information. Some perfectly healthy women are getting tested for genes known to cause or be found in women who have, will have or have had breast cancer. These women normally have a family history that includes breast cancer within more than one family
member. These women undergo genetic testing to determine the presence of altered genes that have been linked to breast cancer. Those two genes are BRCA1 or BRCA2. If they are found altered, this lets the person being tested know their likelihood of getting cancer. Some women may go so far as to have a preventive
mastectomy which is when a healthy woman gets her breasts removed to lessen her risk of breast cancer. This may be considered extreme by some people, but if you know that there is a higher chance that you might experience cancer, many women are willing to make that choice. (2002, National Cancer Institute)
By now you may realize that family history can tell you a lot. What it cannot do is say with a hundred percent certainty that you WILL be afflicted with a particular disease or disorder. As an example, my maternal grandmother has high cholesterol and so does my mother. My paternal grandmother and great
grandmother had diabetes and my father also has diabetes. My mother’s paternal grandfather had throat cancer and her paternal grandmother also had heart problems. Because of this information, I am watching my weight, what I eat and many more aspects of everyday life. I realize that I have an increased chance of
experiencing diabetes, heart trouble, and high c holesterol simply because many of my family members have these. In order to decrease the likelihood of this, I try to control the environmental factors by limiting my sugar, fat and cholesterol intake. There are also instances when there is no family background for
a particular disease or condition but environmental factors and lifestyles may affect an individual. For example, a person with no family history of cancer can still suffer from cancer due to the fact that he or she chooses to smoke or stay out in the sun excessively. Though a well done family history would show
no risk factors, the lifestyle choices of the individual could still result in them experiencing the disease. (2008, SunSmart)
As you can see, your family history can provide you with great amounts of information that can help you stay healthy and live longer. Even the United States Surgeon General acknowledges this fact. In recent years he has instituted a family history initiative, of which the goal is to encourage Americans to find
out the medical history of several generations of their family, in the hopes that this will improve the quality of health and life in America. Knowing your family health history can help save your life and the life of generations to come. (2007, United States Department of Health & Human Services)
Genetic Testing for BRCA1 and BRCA2: It's Your Choice. National Cancer Institute. Retrieved March 6, 2008, from http://www.cancer.gov/cancertopics/factsheet/Risk/BRCA.
Romitti, P,A (2007, 09,01). Utility of Family History Reports of Major Birth Defects as a Public Health Strategy. PEDIATRICS.
Retrieved March 6, 2008, http://pediatrics.aappublications.org/cgi/content/abstract /120/SUPPLEMENT_2/S71?siteid=aapjournals&ijkey=4MXWhHpmgrj7U&keytype=ref .
Skin cancer statistics. SunSmart. Retrieved March 6, 2008, http://www.sunsmart.com.au/ browse.asp?ContainerID=1752 .
U.S. Surgeon General's Family History Initiative . United States Department of Health & Human Services. Retrieved March 6, 2008, http://www.hhs.gov/familyhistory/.