Basic Principles of Genetics<br />How are traits controlled by dominant and recessive alleles?<br />Allelescontrol the inheritance of traits. Some are dominant and some are recessive. Dominant alleles are alleles that show up in the organism whenever it is present. Recessive alleles are alleles that show up whenever a dominant allele is not present. If a dominant allele is present, it will mask the recessive allele.<br />How are traits controlled with co-dominant alleles?<br /> In co-dominance, neither allele is dominant or recessive. This means that neither trait will be masked. For example, if a heterozygous black rabbit mated with a heterozygous white rabbit, their children would be a combination of black and white.<br />Explain how the alleles of two parents combine to express traits in offspring.<br /> The factors that control traits are called genes. The different forms of a gene are called alleles. The gene is for the trait in general. The allele determines the details of the gene. For example, each parent has a gene that will give their child hair. Let’s say that the father has a dominant trait for brown hair, and the mother has a recessive trait for blonde hair. This means that the child will have dark hair. But, the mother has a dominant trait for brown eyes, and the father has a recessive trait for blue eyes. Then, the child will have brown eyes. This is called heredity. <br />+<br />=<br />This is an example of co-dominance.<br />
Human Genome Project<br />When did the project start and how did scientists hope to use this information?<br /> The Human Genome Project was started in October of 1990 and ended in 2003. The original goal was to identify the DNA sequence of every gene in the human genome. The scientists decided that when it was completed, the information would be made public. The scientists would know the DNA sequence of every gene in the human genome. They would also be able to genetically test people, to see if they were at risk of contracting a genetic disease.<br />What are the effects of the Human Genome Project in regards to ethical, legal, and social implications?<br />Unfortunately, the Human Genome Project had flaws. Now that the information was public, the fairness of its use by insurers, employers, and adoption agencies just to name a few was brought up. Also called into question was how the information would be used. Would just anybody be able to access the information? Who owns and controls genetic information? These queries all call into question the ethics of the Human Genome Project. After the Human Genome Project was completed, everybody’s genetic information would be available. This was a problem because now employers and insurers could look into peoples’ genetic information and use it against them. For example, a person could be denied health insurance or a job because they happened to have a gene that could cause them to develop a certain type of cancer. That would be because the insurance company could end up paying for their treatment and the employer would be short an employee because they would be out dealing with their cancer. After GINA was passed, this practice became illegal. The Human Genome Project brought up social concerns as well. What could happen to a person with genes that could cause them to get a disorder if their information went public? How would it change society’s perception of that person? How does information about the genome affect the members of minority communities? These are just some of the unanswered questions brought up by the Human Genome Project. <br />How did the Human Genome Project change current laws such as GINA (Genetic Information Nondiscrimination Act of 2008)? <br />In 2008, GINA was signed into law by President Bush. This law prohibits U.S. insurance companies and employers from discriminating against a person because of their genetic information. This law is important because due to genetic testing, a new technology that was introduced because of the Human Genome Project, a person could see if they were at risk of contracting specific diseases. While this is a good thing, the bad side is that an insurer or employer could look up these test results and discriminate against you because of these results. Because of this legislation, people can take these genetic tests and learn about their risks without having to worry about discrimination.<br />
Genetic Disorders<br />Compare and contrast the three different types of genetic disorders:<br /> 1. single gene disorder<br /> 2. chromosome abnormalities<br /> 3. multifactorial disorders<br />Single gene disorders are hereditary. People with a family history of these disorders are at risk of passing the disorders down to their children, even if the people in question don’t have the disorder themselves. Some examples of single gene disorders are cystic fibrosis, which is where the body creates very thick mucus, which clogs up such important organs such as the lungs and pancreas, and sickle cell anemia, which is where a person’s blood cells take on a crescent moon shape, instead of the typical disc shape. Victims of this disorder are known to have unpleasant symptoms, such as abdominal pain and breathlessness. <br />Chromosome abnormalities are also hereditary. They can be organized into two different groups: numerical abnormalities and structural abnormalities. A numerical abnormality is where the person in question has either not enough chromosomes (monosomy) or too many chromosomes (trisonomy). An example of monosomy is Turner Syndrome, where a female is born with only one sex chromosome, an X. An example of trisonomy is Down Syndrome, where a person is born with 47 chromosomes, instead of the typical 46. This disorder can show physical signs, like small ears and a small mouth, and can also cause delayed mental development. <br /> Structural abnormalities are where the chromosome’s structure is altered. Some examples are deletions, which are where the chromosome is missing or deleted, and duplications, which is where the chromosome is duplicated, resulting in extra genetic material. <br />Multifactorial disorders are not results of natural genetic disorders like single cell disorders and chromosome abnormalities are. This is what sets them apart. Multifactorial disorders come about when an environmental factor and two or more genes combine. An example of a multifactorial disorder is cancer that was brought on by radiation. After nuclear explosions as Hiroshima and Nagasaki in 1945 and Chernobyl in 1986, many people in both Japan and Russia came down with cancer. Even if a person appears to have no problems brought on by the radiation, it can still cause problems. For example, although the nuclear explosion in Chernobyl occurred over twenty years ago, babies in a Ukrainian region near Chernobyl are still being born with birth defects such as undersized heads and eyes. <br />
Genetic Disorders (continued)<br />How can genetic counseling help prospective parents who have a genetic disorder regarding future children?<br />If prospective parents have a family history or are worried about genetic disorders, they would go to a genetic counselor for help. These counselors can tell the parents their chances of having a child with a genetic disorder. They use tools such as Punnett squares, charts that show all the possible results of a genetic cross, karyotypes, which are pictures of all the chromosomes in a cell, and pedigree charts, which are charts that track family members that have or had a specific trait. If parents discover that they are at very high risk of having a child with a genetic disorder, this can cause them to rethink having a child at all, and prompts some to adopt. <br />How are karyotypes used to predict genetic disorders?<br /> If prospective parents want to find out early if their child will have a genetic disorder, they can have a doctor perform a procedure called amniocentesis. This means that the doctor will use quite a long needle and remove some of the fluid surrounding the baby. The fluid holds some of the baby’s cells. After the chromosomes in the cells have been examined, the doctor will create a karyotype, which is a picture of all the chromosomes in a cell. By doing this, the doctor will be able to tell the gender of the baby, and if the baby has the right amount of chromosomes. <br />A karyotype<br />A pedigree chart<br />
The Genetic Information Nondiscrimination Act of 2008 (GINA)<br /> The decoding of the human genome greatly expanded the field of medicine. The new knowledge that was discovered as part of the Human Genome Project gave scientists the potential to develop better treatments against genetic diseases. But Congress also realized the negative side of this. It understood that these improvements could lead to discrimination in the fields of health insurance and employment. GINA was passed in order to prevent this sort of discrimination and to encourage people to take advantage of these developments in genetic testing. Lawmakers called the bill “the first major civil rights act of the 21st century.”<br />
GINA and Health Insurance<br /> GINA has two main parts; Title I and Title II. Title I prevents health insurers from discriminating against a person based on their genetic information. This means that an insurance company is not allowed to request, require, or purchase genetic information. It is also not allowed to set the price of health insurance based on genetic information. An insurer can only use genetic information if a genetic disease has already manifested. <br /> A good reason to keep genetic information private is that if the information was public, it could prevent health insurers from providing any health insurance coverage to people who may or may not develop a genetic disease. They also could only give limited coverage if the genetic predisposition was considered a pre-existing condition. Because of GINA, the price of health insurance would be the same for people who do and do not have a genetic predisposition. <br /> Another good reason to keep genetic information private is that if people have no or limited health insurance as a result of their genetic information being public, then it could prevent them from getting proper care. This would increase human suffering and decrease their quality of life.<br />
GINA and Employment <br />Title II of GINA makes it illegal for employers to discriminate against prospective and current employees because of their genetic information. Legally, an employer is not allowed to involve genetic information in any aspect of employment, specifically things like hiring, firing, salary, job assignments, promotions, layoffs, training, or benefits. According to the U.S. Equal Employment Opportunity Commission (EEOC), “An employer may never use genetic information to make an employment decision because genetic information doesn’t tell the employer anything about someone’s current ability to work.” <br /> If GINA were not in effect, and employers were allowed to genetically test their prospective employees, then people could be considered less suitable for employment because of their genetic information. Just because a person has a gene for a specific disease doesn’t actually mean that the disease will manifest. Denying a person a job on the basis of something that may or may not come true is unfair. This is like saying that a person with brown eyes can do a better job at something than a person with blue eyes. <br /> For people who are already employed and might be at risk for a genetic disease, GINA protects their ability to keep their job and to make the same amount of money as an employee without a genetic problem. Employers are not allowed to go looking for genetic information about their employees. For example, an employer is not allowed to do an internet search, purposely looking for its employees’ genetic information. Employers also can’t eavesdrop on casual conversations among co-workers regarding health and then use it against somebody. If a person with a genetic disease knows that their privacy is protected, it provides them with a better working environment. <br />Percent of Employers <br /> Conducting Tests <br />2001 Study by the American Management Association<br />
GINA and Medical Care<br /> As a result of the Human Genome Project, genetic testing is now more common and is becoming an important part of healthcare. There are over 1,200 genetic tests available to people. These tests can help determine a person’s medical condition and how it can be treated. They can also find out of a person is susceptible to a genetic disease in the future. Genetic tests can also help prospective parents make reproductive decisions. <br /> Before GINA was adopted, many people who might have benefited from genetic testing hesitated to take part in the tests for fear of losing their insurance or their job. Some of them even had the tests done anonymously. With the privacy protection GINA provides, more people who need them can have these tests performed without any fear of discrimination. With the people who really need it taking these tests, doctors can discover a disease or disorder early, and can take proper steps towards treating or preventing it. Treating a potential disease preventively is decidedly less expensive than treatment for the full-blown disease.<br />
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