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.