Study Guide: DNA Technology PDF

Study Guide: DNA Technology 1. Introduction to Biotechnology Definition: Biotechnology is the use of living organisms, cells, and biological systems to develop technologies and products for applications in medicine, agriculture, and industry. It includes both traditional and modern approaches. Met...

Study Guide: DNA Technology 1. Introduction to Biotechnology Definition: Biotechnology is the use of living organisms, cells, and biological systems to develop technologies and products for applications in medicine, agriculture, and industry. It includes both traditional and modern approaches. Methods of Changing Traits 1.​ Artificial Selection (Selective Breeding) ○​ Choosing specific organisms to reproduce desirable traits. 2.​ Inbreeding ○​ Definition: Mating closely related individuals to preserve specific traits. ○​ Example: Holstein cows for high milk production. ○​ Advantages: Predictable traits, stronger breed lines. ○​ Disadvantages: Increased risk of genetic disorders due to recessive genes. 3.​ Hybridization ○​ Definition: Crossing different species to combine desirable traits. ○​ Example: Pineberries (cross between two strawberry species). ○​ Advantages: Increased genetic diversity, enhanced growth and survival. ○​ Disadvantages: Hybrid offspring may be sterile (e.g., mules). 4.​ Polyploidy ○​ Definition: A mutation resulting in multiple sets of chromosomes. ○​ Example: Wheat, bananas. ○​ Advantages: Larger, stronger plants. ○​ Disadvantages: Lethal in animals due to genetic complications. 2. DNA Manipulation Techniques Restriction Enzymes ​ Definition: Enzymes that cut DNA at specific restriction sites or palindromic sequences. ​ Vocabulary Terms: ○​ Palindrome: A DNA sequence that reads the same forward and backward.  ○​ Complementary Tail: The sticky ends created by restriction enzymes that allow for DNA fragments to be joined together. ​ Types of Cuts: ○​ Sticky Ends: Overhanging sequences that can be joined with complementary DNA. ○​ Blunt Ends: Straight cuts with no overhangs, making recombination more difficult. Polymerase Chain Reaction (PCR) ​ Definition: A method to amplify DNA for analysis. ​ Steps: ○​ Denaturation (94°C): DNA strands separate. ○​ Annealing (55°C): Primers bind to target sequences. ○​ Extension (74°C): DNA polymerase builds new strands. ​ Uses: ○​ Crime scene investigations. ○​ Diagnosing genetic diseases. Gel Electrophoresis ​ Definition: A technique used to separate DNA fragments by size. ​ Steps to Create a DNA Fingerprint: ○​ DNA is extracted and cut using restriction enzymes. ○​ DNA fragments are loaded into a gel. ○​ An electric current is applied, moving smaller fragments faster than larger ones. ○​ A DNA fingerprint pattern is created, unique to each individual. ​ Vocabulary Terms: ○​ STR (Short Tandem Repeats): Repeated sequences used in forensic identification. ○​ RFLP (Restriction Fragment Length Polymorphism): Uses restriction enzymes to analyze DNA fragment patterns. ○​ Difference: STR is faster and more commonly used in forensics than RFLP, which requires larger DNA samples. 3. Genetic Engineering & Recombinant DNA Definition: The direct manipulation of an organism’s DNA to introduce new traits. Steps in Genetic Engineering: 1.​ Identify the desired gene (e.g., insulin gene). 2.​ Use restriction enzymes to cut both the gene and plasmid. 3.​ Insert the gene into a plasmid, creating recombinant DNA. 4.​ Introduce recombinant DNA into host cells using transformation. 5.​ Host cells replicate and express the gene, producing proteins. Key Vocabulary: ​ Recombinant DNA: DNA from different sources combined into one. ​ Plasmids: Small circular DNA in bacteria used for gene transfer. ​ Transgenic Organisms: Organisms with inserted foreign DNA. ​ Transformation: Process where a cell takes in recombinant DNA. 4. Gene Therapy ​ Definition: A technique to replace, remove, or repair faulty genes. ​ Methods: ○​ Knockout Therapy: Faulty genes are replaced with functional ones. ○​ Viral Vectors: Viruses are engineered to insert correct genes into a patient’s cells. ​ Why Gene Therapy is Not Permanent: ○​ The inserted gene may not integrate permanently into the genome. ○​ The immune system may attack treated cells. ○​ New cells may not inherit the corrected gene. Diseases Treated: ​ Sickle-cell disease ​ AIDS ​ Cancer ​ Hemophilia 5. Cloning & The Human Genome Project Cloning ​ Definition: Producing genetically identical copies of an organism. ​ Types:  1.​ Reproductive Cloning: Produces a new organism (e.g., Dolly the sheep). 2.​ Therapeutic Cloning: Creates stem cells for medical use. 3.​ Molecular Cloning: Copies specific DNA fragments. Human Genome Project (HGP) ​ Definition: A project (1990-2003) that mapped all human genes. ​ Applications: ○​ Identifying genetic disorders. ○​ Developing personalized medicine. 6. CRISPR: Gene Editing Technology ​ Definition: A tool that allows scientists to precisely edit genes. ​ Process: ○​ CRISPR targets a specific DNA sequence. ○​ Cas9 enzyme cuts the DNA at the target site. ○​ Scientists modify or replace the gene. ​ Uses: ○​ Treating genetic disorders (e.g., sickle-cell disease). ○​ Developing disease-resistant crops. 7. CODIS: DNA Identification System ​ Definition: The Combined DNA Index System (CODIS) is a forensic database used for DNA profiling. ​ Usage: ○​ Law enforcement: Identifies criminals from DNA evidence. ○​ Missing persons cases: Matches unknown DNA to relatives.