Saturday, February 17, 2007

Biology: Section 13-3 Review

Biology: Section 13-3 Review

1.) List two types of medical products that can be produced using DNA technology.

Two types of medical products that can be produced using DNA technology are the human growth hormone which is used to treat dwarfism and colony-stimulating factors which are used to treat immune-system deficiencies by stimulating the production of white blood cells.

2.) What is a vaccine, and what are the benefits of producing vaccines using DNA technology?

A vaccine is a solution that contains a harmless version of a virus or a bacterium. Traditionally, vaccines have been made of disease-causing agents known as pathogens – that have been treated chemically or physically so that they no longer can cause disease. DNA technology can be used for preparing vaccines, which may be safer than some more traditional methods. DNA technology can also be used to alter the genome of a pathogen so that it can no longer cause disease.

3.) List three traits for which genes are being transferred into crop plants.

By transferring genes for enzymes that are harmful to plants, scientists have now made it possible for plants to be more productive for farmers and immune to things such as hornworms and types of fertilizer. Also, it has now become possible for plants not to need fertilizer. Although these major developments are liked by many, there are still some people against the genetic engineering of plants.

4.) What benefit are plants that contain nitrogen fixing gene transported from bacteria?

Plants that contain a nitrogen fixing gene that is transported from bacteria are very beneficial in that they do not need to be fertilized. With out this genetically engineered trait, farmers have to extensively apply nitrogen fertilizers to the soil. Currently, researchers are working to isolate and clone genes from nitrogen-fixing bacteria and transplant this gene into plants.

5.) Describe two potential safety and environmental problems that could result from genetic engineering.

Many people in the United States are concerned that genetically engineered foods are potentially hazardous and unsafe for many people as well as the environment. Some concerns that people have include that genetically engineered foods could contain toxic proteins or substances that create allergies to people who consume them. Also, some genetically engineered crops could have the potential to spread into the wild and wipe out native plant species. In doing this genes could be exchanged, resulting in the formation of a “super weed” that could take over large areas of land because they are immune over native crops.

Love and Race -- Critical Thinking Questions

Assignment: In “The New World Reader,” reread the essay, “Love and Race,” written by Nicholas D. Kristof. Once the reading is complete, answer all of the questions for critical thinking.

1.) What is your opinion of interracial love? What assumptions and attitudes do you bring to the subject? How open are you to an essay entitled “Love and Race”? Why would such a topic invite – almost demand – careful critical thinking? What assumption do you think that Kristof makes about his readers?

After reading the essay, “Love and Race,” written by Nicholas D. Kristof, I was able to gather many of my own personal opinions. First of all, I would like to start by saying that I agree completely that interracial intimacy is a positive step in showing that our society has and is becoming more racially tolerant. Secondly, I would like to comment that the title is indeed a good fit for this particular essay because it describes the content of the essay very simply yet very well. Third, such a topic would guarantee the need for critical thinking for it a rather complex matter with a good deal of history behind it. If you have ever studied American History or the Civil War, you know this first hand. Racism and each individual’s thoughts and opinions can vary greatly. This is why this topic requires very careful critical thinking. Finally, I would like to conclude by saying that Kristof probably assumes that his readers are younger, probably in high school or college, he most likely assumes that they are liberal and agree that racism is wrong, and he also probably assumes that his readers follow the developments of and with this trend in their everyday lives and know some history behind the topic as well.

2.) Why does Kristof refer to the University of Mississippi (Ole Miss) at the beginning and the end of his essay (paragraphs 3 and 15)? When answering this question, use your knowledge of civil rights history to broaden your understanding of Kristof’s purpose.

I would assume that Kristof refers to the University of Mississippi (Ole Miss) in the third and fifteenth paragraphs of his essay because he is trying to show how different students at the university might have felt about this particular topic of interracial dating and love.

In paragraph three, a black student of the university quotes “I will say that they are always given a second glance.” In this case, I believe that this student is referring that those who interracially date are most often looked down upon by other members of the academic community. In paragraph fifteen, Kristof was looking forward to gathering research on this topic however was not able to find anyone willing to speak publicly about the topic.

Some reasons for individuals not wanting to speak publicly could include that they are afraid that others might look down upon them or that their opinions might be considered bad or might have the tendency to stir up controversy. It is probably a combination of a good many things. If you want to look at it from a civil rights perspective, many people in the southern United States are still in agreement with old beliefs of racism and are uncomfortable with our ever changing society.

However, back to the main point, Kristof’s main reason for referring to Ole Miss was to show how members (students) of a particular academic community felt towards the uprising trend of interracial dating. Whether they were in agreement or not, he wanted to display all opinions and beliefs.

3.) Where does Kristof use description and narration to organize part of the essay? What is the effect?

When reading the essay “Love and Race,” I felt that a large portion of the essay used description and narration as a form of organization. I felt this to be most demonstrated in paragraphs four through eleven. However I would say that the author, Nicholas D. Kristof used narration and description throughout the entire essay except for a few sentences once in awhile. Using this form of organization, I was very easily able to understand the author’s message and what the essay was all about.

4.) Kristof employs numerous expository strategies in this essay. Locate and identify them, explaining what they contribute to the substance and the organization of the essay.

Some expository strategies used by Kristof include the following:

Ø In the introduction, Kristof explains the content of his essay and tells his audience about the growing trend of interracial dating.

Ø In paragraph 3, C.J. Rhodes, a black student at Ole Miss quotes “I will say that they are always given a second glance.” In order to clarify what Rhodes means by this quote, Kristof responds by writing “He adds that there are still misgivings about interracial dating, particularly among black women and a formidable amount of “white Southerners who view this race-mixing as abnormal, frozen by fear to see Sarah Beth bring home a brotha.” With this given response, I feel that Kristof is able to clarify Rhodes’ statement and adds more definition to its meaning.

Ø In paragraphs eight and nine, Kristof resorts to explaining some history of how racial behaviors had affected our society in the past. This in itself was an expository strategy to help the essayist and the reader correlate an understanding together of the central meaning of interracial dating.

Ø Paragraph thirteen states “These days, interracial dating can be seen on the big screen, on TV shows and in the lives of some prominent Americans. Former Defense Secretary William Cohen has a black wife, as does Peter Norton, the software guru. The Supreme Court justice Clarence Thomas has a white wife.” Paragraph fourteen goes on to say “I find the surge of interracial marriage to be one of the most positive fronts in American race relations today, building bridges and empathy. But it’s still in its infancy. As I am sure you are aware, paragraph thirteen is suggesting to the reader that he or she probably has seen interracial relationships in their everyday lives whether they may realize it or not where paragraph fourteen states the author’s own personal opinion.

Ø The closing paragraph is simply stating that Mr. Kristof is in belief that racial differences will soon blur and that all will be seen differently within time to come. You may have noticed that the ending paragraph and paragraph fourteen are both very much alike.

5.) Does Kristof construct an argument in this essay or is he simply reporting a cultural development?

In all honesty, each individual may see Kristof’s writing in a different light. However, since this particular question is asking me to tell whether Kristof is constructing an argument or is reporting a cultural development, I would have to say from my perspective that he is reporting a cultural event that has the potential for being an argument. From the context that is provided within the essay, you see the Kristof is reporting the cultural development that is taking place in our everyday lives. However, if you are to take a closer look, you will likely note that he has listed some of his own personal opinions. As is the case with almost all opinions, not everyone is in agreement. Therefore when the author lists his personal opinions he is allowing others to agree or disagree while at the same time, reporting a cultural development.

Biology: Section 13-2 Review

Biology: Section 13-2 Review

1.) Define DNA fingerprint and discuss the accuracy of using DNA fingerprints to establish relatedness.

A DNA fingerprint is a pattern of bands made up of specific fragments from an individual’s DNA. The banding patterns of DNA fingerprints from two different individuals may be compared to establish whether or not they are related. The members of two different species may also be compared using DNA fingerprints to see how closely they are related. In regards to the accuracy, DNA fingerprints can vary depending on how unique one’s prints are. The complete nucleotide sequence of each individual is certainly unique for each person, except in the case of identical twins, who share identical DNA.

2.) Describe the major steps and techniques involved in preparing a DNA fingerprint.

The method for preparing a DNA fingerprint is called restriction fragment length polymorphism (RPLF) analysis. RPLF analysis involves extracting DNA from a specimen of blood or other tissue and cutting it into fragments using restriction enzymes. The fragments are then separated using a technique called gel electrophoresis. The finial step in making a DNA fingerprint is making visible only the bands that are being compared. The DNA fragments that have been separated on the gel are split into single chains and are then blotted onto filter paper.

3.) Compare the polymerase chain reaction and DNA replication.

To make a DNA fingerprint, a certain amount of DNA is needed. If the source is limited, the polymerase chain reaction can be used to quickly make selected segments of the available DNA. In this sense, DNA is replicated by the polymerase chain reaction making the two processes very similar. However according to the Oak Ridge National Library, DNA replication is defined as the using existing DNA as a template for the synthesis of new DNA strands. In humans and other eukaryotes, replication occurs in the cell nucleus. The polymerase chain reaction is a process more commonly used by geneticists.

4.) Describe the purpose of the Human Genome Project, and name the potential uses of the information collected in the project.

To the Human Genome Project there are two goals. The first goal of the Human Genome Project is to determine the entire nucleotide sequence of the entire human genome – approximately 3 billion nucleotide pairs, or about 100,000 genes. In addition, the human genome is being compared with other organisms on the quest to provide insight on fundamental questions about how genes are organized, how gene expression is controlled, how cellular growth and differentiation are under control, and how evolution occurs. The Human Genome Project has the potential for expanding research with gene therapy, the treating of a genetic disorder by introducing a gene into a cell or by correcting a gene defect in a cell’s genome. With gene therapy, disorders and illnesses such as hemophilia B, lung cancer, AIDS, ovarian cancer, and brain diseases have the potential for a cure.

5.) What is gene therapy, and how does it differ from traditional treatments for diseases?

Gene therapy is the treating of a genetic disorder by introducing a gene into a cell or the correcting of a gene defect in a cell’s genome. This treatment differs from many in that it is not used to benefit the patient but instead, helps to prevent a particular genetic disorder from being passed onto future generations. This is so because the genes used for treatment are inserted into the cell’s nucleus rather than directly on the chromosome.

Biology: Section 13-1 Review

Biology: Section 13-1 Review

1.) Define genetic engineering.

Genetic engineering is the application of molecular genetics for practical purposes. Genetic engineering can be used to identify genes for specific traits or to transfer genes for a specific trait from one organism to another.

2.) What role do restriction enzymes play in genetic engineering?

Restriction enzymes are bacterial enzymes that are used to cut DNA molecules into more manageable pieces. Restriction enzymes recognize specific sequences of nucleotides. They then cut the DNA at a specific site within the sequence.

3.) How do sticky ends function?

A single-chain of DNA, called sticky ends are created on each DNA segment cut by the restriction enzyme. The function of a sticky end is to readily bind to complementary chains of DNA. Thus, pieces of DNA that have been cut with the same restriction enzyme can bind together to form a new sequence of nucleotides.

4.) Explain the role of cloning vectors in genetic engineering.

The role of a cloning vector is to serve as a carrier that is used to clone a gene and transfer it from one organism to another. Many bacteria containing a cloning vector are known as plasmids, a ring of DNA found in a bacterium in addition to its main chromosome.

5.) What steps are used to produce insulin using recombinant DNA and bacteria?

The combination of DNA from two or more sources is called recombinant DNA. Inserting a donor gene, such as a bacterial plasmid, results in a recombinant DNA molecule. Recombinant DNA is produced when a plasmid is removed from a bacteria cell and a donor gene is inserted into the plasmid. To apply this to insulin, this would result in its mass production.