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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 :

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Biotechnology - History

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  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

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