Copyright Pearson Prentice Hall 14–3 DNA Fingerprinting and the Human Genome Project Photo credit: Richard Hutchings/Photo Researchers, Inc. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Human DNA Analysis DNA Fingerprinting DNA fingerprinting compares images of DNA to determine relationships among individuals. No two people’s fingerprints are the same. Twins have primarily the same DNA. DNA samples can be obtained from blood, sperm, and hair strands with tissue at the base. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Human DNA Analysis DNA fingerprints are developed with Gel Electrophoresis. Gel Electrophoresis is a method of separating DNA fragments by passing an electric current through a gel. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Human DNA Analysis Step 1: Restriction enzymes are used to cut the DNA into smaller pieces. Copyright Pearson Prentice Hall
What is a restriction enzyme? A protein that recognizes a specific, short nucleotide sequence and cuts the DNA only at that specific site. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Step 2: DNA pieces are then placed in a gel between positive and negative electrodes. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Objects with the same electrical charge repel each other. DNA has a negative charge, so the DNA pieces move away from the negative electrode toward the positive electrode. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Gel electrophoresis sorts the DNA pieces according to size. Different size pieces move through the gel at different rates. Smaller pieces move quick and farther through the gel versus larger pieces. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall As DNA pieces are sorted by size, they appear as lines of different lengths on the gel. The resulting lines are called DNA fingerprints! Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Human DNA Analysis DNA Fingerprint: Does the DNA fingerprint from the crime scene match with Suspect 1, 2, or 3? Photo credit: ©Leonard Lessin/Peter Arnold, Inc Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall DNA Fingerprints are used: In forensic science to solve crimes. To determine a child’s mother or father. Identify related species Copyright Pearson Prentice Hall
The Human Genome Project All the hereditary information of an organism makes up its genome. Copyright Pearson Prentice Hall
The Human Genome Project In 1990, scientists began the Human Genome Project. One goal was to identify and map the locations of all the genes in human DNA. Second goal was to determine the sequence of the 3 billion base pairs that make up human DNA. Copyright Pearson Prentice Hall
The Human Genome Project Scientists use their data from the project to determine whether people carry the genes for certain diseases. Scientists then develop treatments Copyright Pearson Prentice Hall
The Human Genome Project The results of the Human Genome Project have led to the possibility of using gene therapy to treat genetic disorders. Gene therapy involves replacing a defective or missing gene in a person’s genome. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall There are several problems of using gene therapy. The need to find the exact gene that cause a specific disease can be difficult. It could harm people since viruses are used to transport the new genes. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Gene Therapy The patient is infected with the modified virus particles, which should carry the gene into cells to correct genetic defects. Gene therapy is the process of changing the genes that cause a genetic disorder. This drawing shows how a virus might be used to deliver the gene for normal hemoglobin into a person’s bone marrow. Copyright Pearson Prentice Hall