The practical use and application of biology. Biotechnology The practical use and application of biology.

DNA Fingerprinting DNA Fingerprint: The analysis of sections of DNA in order to identify individuals when there is only body matter (blood, spit, etc.) left at the crime scene. Gel Electrophoresis: This is the tool used to create a DNA Fingerprint. Separates pieces of DNA by size by pulling them through a bed of agarose gel. Larger pieces don’t move far, smaller pieces move quite a bit. Larger piece DNA Smaller piece DNA

DNA Fingerprinting by Gel Electrophoresis Step 1: Restriction Digestion Restriction digestion - the process of breaking down DNA into smaller fragments by targeting a specific nucleotide sequence on the DNA ladder and breaking the phosphate bonds at the beginning and the ends of the sequences. This is accomplished using restriction enzymes (in the picture on the right, the scissors represent the restriction enzyme) which are enzymes that are restricted to breaking apart the DNA to a certain area within the entire DNA sequence of an organism. If the gene a scientist is looking for is present in a sample, a band will appear. If the gene is absent, there will be no band in the area it is known to occupy.

Step 2: PCR – Polymerase Chain Reaction PCR is a method of amplification ~ Process by which DNA fragments are copied to increase the amount of DNA available for testing. Sections of DNA prepared by restriction digestion are heated in a mixture with loose nucleotides and DNA polymerase. DNA “unzips” in the heat, and loose nucleotides match up with the bases on the unzipped halves. DNA polymerase bonds the nucleotides together to form new strands of DNA. Takes about 2 hours. This process may be repeated to make even more DNA.

Step 3: Gel Electrophoresis Fragments of DNA are sorted by size. The shorter the DNA fragment, the faster it will move toward the positive terminal. Longer fragments move a lot more slowly and stay toward the end with the wells (negative terminal). Wells Negative Terminal DNA is negatively charged, so to pull it through the gel, the positive terminal of the battery must be hooked up to the end opposite the wells. Positive Terminal

Reading the DNA Fingerprint Matching band patterns indicate a relationship between individuals.

Genetically Modified Organisms GMO’s are organisms whose DNA has been genetically altered to improve the function of the organism. Uses: Human insulin production from bacteria by inserting the human gene for insulin in the bacterial plasmid (bacterial transformation is shown in the pic) Crop resistance to pests and drought. Increasing the vitamin content in foods. Controversy: “Frankenfoods” Could have a negative impact on food chains and the environment

Transgenic Organism- a type of genetically modified organism that has had genes from other organisms inserted into their DNA Golden rice Glofish Tobacco plant with firefly gene Transgenic mice- have human genes inserted in them to help in studies of human disease

How are GMO’s are created? Recombinant DNA (rDNA) Recombinant DNA- genetically engineered DNA prepared by transplanting or splicing genes from one species into the cells of a host organism of a different species. Such DNA becomes part of the host's genetic makeup and is replicated. Recombinant DNA technology is a technique that uses DNA molecules from different sources, combining them into one molecule to create a new set of genes This DNA is then transferred into an organism, giving it modified genes

Cloning Making offspring that are genetically identical to the parent. Dolly the sheep was the first mammal cloned and lived 6 years (1996-2003). Dolly was born to three mothers 1. provided the egg 2. provided the DNA 3. carried the cloned embryo to term Can we bring extinct animals back to life? Cloning Video

Human Genome Project Humans have about 30,000 genes. This is a project initiated by the government to map out the base sequence of human DNA. Goal: To map all of the A, T, C and G base pairs on human DNA. Hope: Identifying all of the genes on DNA will lead to finding cures for disease, and finding beneficial ways to use genes. Findings: Humans have about 30,000 genes. Any two human’s DNA is 99.9% identical.

Stem Cells Stem cells ~ These are undifferentiated (not a specific type of) cell that have the potential to become any type of cell. Stem cells have not turned off any genes. Stem cells could be used to replace cells that are damaged or dying in a patient or a patient’s organ. Natural stem cells: Bone marrow and umbilical cord blood. Controversy: Embryonic stem cells

Gene Therapy: The process of changing the gene that causes a genetic disorder to a a normal, healthy gene. This is accomplished by using a virus to enter a cell and release the correctly engineered DNA.

Nova: Cracking the Code of Life