1 / 15

Biotechnology - History

Biotechnology - History. Selective Breeding. Selective Breeding. The Wide Variety of Animals & Plants Used By Humans, Have Been Developed By Selective Breeding – Allowing Only Those Animals & Plants With Desired Characteristics Are Allowed To Reproduce. Selective Breeding. Key Concept :

moses
Download Presentation

Biotechnology - History

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Biotechnology - History Selective Breeding

  2. Selective Breeding The Wide Variety of Animals & Plants Used By Humans, Have Been Developed By Selective Breeding – Allowing Only Those Animals & Plants With Desired Characteristics Are Allowed To Reproduce.

  3. Selective Breeding Key Concept: Humans Use Selective Breeding To Pass Desired Traits On To The Next Generation of Organisms • Apples, Corn, Potatoes • Dogs, Cattle, Mice, Yeast

  4. Selective Breeding • Luther Burbank 1849-1926 • 800 Varieties of Plants • Disease Resistant Potatoes

  5. Selective Breeding - Hybridization Crossing Dissimilar Individuals To Bring Together The Best Of Both Organisms • Often Hardier Than Parents • Disease Resistance + Increased Food Producing Capacity

  6. Selective Breeding - Hybridization Postzygotic Barriers • Reduced Hybrid Viability • Embryos Don’t Develop • Reduced Hybrid Fertility • Offspring Vigorous but Sterile • Hybrid Breakdown • 1st Generation Viable & Fertile • 2nd Generation Feeble & Sterile

  7. Selective Breeding - Inbreeding • Used To Maintain A Desired Characteristic • Dog Breeds • Higher Risk of Homozygous Recessive Alleles for Genetic Defect. • Blindness & Joint Problems In German Shepherds & Golden Retrievers

  8. Increasing Variation Key Concept: Breeders Can Increase The Genetic Variation In A Population By Inducing Mutations

  9. Increasing Variation • Selective Breeding Impossible Without A Diverse Gene Pool • Importance Of Diversity In Wild Populations • Mutations Induced Through • Radiation • Chemicals

  10. Increasing Variation • Most Mutations Undesirable • Offspring Destroyed • Few Mutations Desirable • Breed To Maintain

  11. Increasing VariationNew Kinds of Bacteria • Easy To Induce Mutations In Millions At Once • Mutations Particularly Useful • Produce Oil Eating Bacteria • Plastic Eating Bacteria

  12. Increasing VariationNew Kinds of Plants • Drugs Disrupt Chromosomal Separation During Meiosis • Polyploidy • Offspring 2X or 3X Chromosomes • Usually Fatal For Animals • Tolerated & Useful In Plants

  13. Increasing VariationNew Kinds of Plants Polyploidy • May Instantly Produce A New Species Larger & Stronger Than Their Diploid Relatives • Bananas, Strawberries, Oats, Cotton, Tobacco, Wheat

  14. Increasing Variation – New Kinds of Plants Allopolyploid • Two Different Species From the Same Genus To Form A Polyploid Hybrid • Bread Wheat – Triticumaestivum • 8000 years ago • Cultivated Wheat & Wild Grass

  15. Allopolyploid Polyploidformed between two closely related species

More Related