Presentation on theme: "13–1Changing the Living World A.Selective Breeding 1.Hybridization 2.Inbreeding B.Increasing Variation 1.Producing New Kinds of Bacteria 2.Producing New."— Presentation transcript:
13–1Changing the Living World A.Selective Breeding 1.Hybridization 2.Inbreeding B.Increasing Variation 1.Producing New Kinds of Bacteria 2.Producing New Kinds of Plants Section 13-1 Section Outline Go to Section:
Selective Breeding For centuries, humans have chosen desirable traits for dog breeding. This type of trait selection is called selective breeding. There are two types of selective breeding: 1. Hybridization 2.Inbreeding
Hybridization Luther Burbank (1849-1926) is deemed as one of the greatest selective breeders. He developed disease- resistant potatoes as well as many other varieties in plants. Burbank often crossed different individuals to bring together the best of each organism. This is called hybridization. Ex. Disease resistance x high food-producer
Inbreeding *Risky business: Inbreeding causes individuals to be genetically similar, thus increasing the chances of bringing two recessive alleles together. ( Ex. Blindness in German Shepherds.) After the desired qualities are established, many breeders then inbreed or continue to breed individuals together with similar characteristics.
Manipulating DNA In the past, scientists had to rely on variation (natural and mutation generated) to produce changes in DNA. Now, scientists can change DNA because: 1. Structure of DNA is known 2. Able to cut, extract and transfer pieces of DNA 3. Make unlimited copies of DNA
Genetic Engineering Making changes in the DNA code of a living organism. 3 Basic Steps: DNA extraction Cutting DNA Separating DNA
Cell transformation the Big Picture! During transformation, a cell takes in DNA from outside the cell. (manipulated?) This external DNA becomes part of the cell’s DNA. Ex. Griffith’s pneumonia experiments.
which crosses consists of Selective Breeding for example Inbreeding Hybridization Similar organisms Dissimilar organisms for example Organism breed A Organism breed B Retains desired characteristics Combines desired characteristics which which crosses which Section 13-1 Concept Map Go to Section:
Transgenic Organisms Transgenic organisms contain genes from other organisms. (ex: Firefly ‘glow’ gene inserted into tobacco plant) *Biotechnology- new industry resulting from genetic engineering.
Transgenic Microorganisms Transgenic bacteria are used to produce many useful substances for health and industry. Why bacteria? 1. Reproduce quickly 2. Easy to grow Examples: Human proteins; cheap and abundant Human insulin
Transgenic Animals Used to study genes Ex. Mice with immune systems like humans-> study diseases Improve the food supply Ex. Livestock with growth hormone-> faster growing and less fatty meat *Future animals that produce human proteins.
Transgenic Plants Important part of food supply. Ex. Many contain genes that produce a natural insecticide. No need for synthetic pesticides. Ex. Rice with added vitamin A.
Cloning A clone is a member of a population of genetically identical cells produced from a single cell. *1997- Dolly was cloned in Scotland by Ian Wilmut. In the news today: Cloned embryos okayed in Scotland.
Cloning Section 13-4 Flowchart A body cell is taken from a donor animal. An egg cell is taken from a donor animal. The fused cell begins dividing, becoming an embryo. The nucleus is removed from the egg. The body cell and egg are fused by electric shock. The embryo is implanted into the uterus of a foster mother. The embryo develops into a cloned animal. Go to Section:
A donor cell is taken from a sheep’s udder. Donor Nucleus These two cells are fused using an electric shock. Fused Cell The fused cell begins dividing normally. Embryo The embryo is placed in the uterus of a foster mother. Foster Mother The embryo develops normally into a lamb—Dolly Cloned Lamb Egg Cell An egg cell is taken from an adult female sheep. The nucleus of the egg cell is removed. Section 13-4 Figure 13-13 Cloning of the First Mammal Go to Section: