Genetic Engineering Chapter 13

Changing the Living World Selective breeding Breeding animals with characteristics we want to produce offspring with those Plants – Potatoes or flowers Animals – dogs or farm animals

Changing the Living World Hybridization Cross different individuals to get offspring with favorable traits The result is a hybrid – an individual produced from the crossing of two different organisms.

Changing the Living World Inbreeding Breed similar individuals over and over to get offspring with favorable traits

Changing the Living World Increasing variation Inducing mutations Radiation Chemicals Produce mutants – an individual showing the mutation

Changing the Living World Producing new bacteria Small size allows for millions to be treated Oil eating bacteria

Changing the Living World Producing new plants Chemicals that prevent chromosomal separation Polypoidy Larger and stronger plants

13-2 Manipulating DNA How can scientists manipulate the code? Scientists use their knowledge of the structure of DNA and its chemical properties to study and change DNA molecules.

13-2 Manipulating DNA Tools of Molecular Biology Genetic Engineering Making changes in the DNA code of a living organism DNA Extraction Open a cell (mechanical and chemical methods) Use a chemical to separate the DNA from the rest of the cell parts (an alcohol)

13-2 Manipulating DNA Cutting DNA DNA molecules are very long Restriction enzymes Enzymes that cuts DNA at a specific sequence of nucleotides Sticky ends – these are the cut ends of the DNA

13-2 Manipulating DNA Separating DNA Gel electrophoresis A mixture of DNA fragments is placed at one end of a porous gel (negative end), and an electric voltage is applied to the gel The molecules will move from negative to positive

13-2 Manipulating DNA

13-2 Manipulating DNA Using the DNA Sequence Once it is separated it is manageable It can now be Read Studied Changed

13-2 Manipulating DNA Reading the Sequence How do you read unknown DNA? You can use: DNA Polymerase Four nucleotides Chemical markers

13-2 Manipulating DNA Cutting and Pasting DNA synthesizers Enzymes join artificial pieces of DNA with natural pieces Recombinant DNA Enzymes join genes from one strand of DNA with genes from another strand of DNA

13-2 Manipulating DNA Making Copies PCR or Polymerase chain reaction Photocopying DNA over and over Use strands of DNA that are called primers

13-3 Cell Transformation Transformation When a cell takes in foreign DNA and joins it with the existing DNA This external DNA becomes part of the cells DNA

13-3 Cell Transformation Transforming Bacteria Foreign DNA is joined to plasmid Plasmid – small, circular DNA molecule Genetic marker – a gene that makes it possible see which bacteria are carrying the plasmid (that is marked) and which bacteria are not.

13-3 Cell Transformation Transforming Plant Cells Using bacterium that normally infect plant cells and cause tumors Taking away the cell wall some plant cells will take up DNA on their own If successful recombinant DNA will be found in a chromosome of the cell

13-3 Cell Transformation Transforming Animal Cells DNA can be injected directly into the nucleus of an egg Enzymes help insert the new DNA into the eggs existing DNA New DNA contains markers that tell which cells picked up the DNA

13-4 Applications of Genetic Engineering Transgenic Organisms Organisms that contain genes from other species Firefly and tobacco plant Genetic engineering has increased the growth of biotechnology

13-4 Applications of Genetic Engineering Transgenic microorganisms Bacteria reproduce quickly Uses: Can grow human proteins Insulin, growth hormone, and clotting factor

13-4 Applications of Genetic Engineering Transgenic Animals Mimic human body for testing Faster growing animals No more food poisoning Grow human proteins

13-4 Applications of Genetic Engineering

13-4 Applications of Genetic Engineering Transgenic Plants Natural insecticide Resist weed killing chemicals Food resistant to spoiling Weather resistant plants Grow vitamins or proteins

13-4 Applications of Genetic Engineering Cloning Clone - A member of a population of genetically identical cells produced from a single cell Dolly – The cloned sheep from 1997 Save endangered species