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Mutation Theory of Hugo de Vries | Saltation Evening Primrose | NEET Class 12 | Neela Bakore

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Mutation Theory of Hugo de Vries | Saltation Evening Primrose | NEET Class 12 | Neela Bakore

135 194 просмотра · 10 лет назад
Neela Bakore Tutorials
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135 194 просмотра · 10 лет назад
◀ PREVIOUS VIDEO (12/22): Darwin's Theory of Natural Selection    • Darwin's Theory of Natural Selection | Sur...   ▶ CURRENT VIDEO (13/22): Mutation Theory of Hugo de Vries    • Mutation Theory of Hugo de Vries | Saltati...   ▶ NEXT VIDEO (14/22): Neo-Darwinism (Modern Synthetic Theory)    • Neo-Darwinism Modern Synthetic Theory | Ge...   🔗 Full Playlist:    • Плейлист   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Evolution by sudden leaps — that's Hugo de Vries' Mutation Theory! This video covers his ideas based on experiments with evening primrose. 📌 Topics Covered: • Hugo de Vries (1901) and his mutation theory • Experiments on Oenothera lamarckiana (evening primrose) • Concept of Mutation — sudden, large, heritable change (Saltation) • De Vries proposed mutations (not gradual changes) drive new species • Saltation — single-step large mutation creating a new species • Differences from Darwinism: Darwin: gradual, small variations; De Vries: sudden, large mutations Darwin: selection is key; De Vries: mutation is key • Limitations of the mutation theory • NEET MCQ on Hugo de Vries and mutation theory ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Transcript with Timestamp 0:00 Third theory: Mutation Theory — proposed by Hugo de Vries 0:55 Darwin noticed sudden variations (called 'sports') but did not focus on them 1:19 Hugo de Vries worked on evening primrose — Oenothera lamarckiana (2n=14) 2:01 Self-pollination experiments: majority minor variations; very few major variations 3:42 Major variations: size of flower, color, position of flower, size of plant 4:14 Major variation plants had different chromosome numbers: 16, 20, 22, 24, 28, 30 etc. 5:00 Most different plant: Oenothera gigas 5:26 Sudden change = discontinuous variation = mutation 5:55 Mutations are responsible for evolution, not slow continuous variations 7:04 Example 1: Ancon sheep — extremely short legs appeared suddenly — could not jump fences 7:57 Example 2: similar experiments by MacDougall and Schell — same results 8:29 Example 3: polyploidy commonly found in plants — sudden change 9:28 Criticism: mutations do not occur as frequently in nature as in his experiments 10:42 Only focused on chromosomal number changes — missed point mutations ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Amazon Brand Store at https://www.amazon.in/neelabakoretuto.... Complete Study Notes (11th and 12th) are available at: https://amzn.to/3K4Li7k Complete Study Notes for 12th are available at: https://amzn.to/3PRhWjm Complete Study Notes for 11th are available at: https://amzn.to/4uw1hBa The study notes for this unit Genetics & Evolution are available at https://amzn.to/2Sh27jW The study notes for other units: - Diversity in Living World - https://amzn.to/3r8qkyH Structural Organisation in Plants and Animals - https://amzn.to/3r2cxmZ Cell: Structure and Functions - https://amzn.to/2GPagcm Plant Physiology - http://amzn.to/2EZR5HS Human Physiology - http://amzn.to/2DA46ea Reproduction - https://amzn.to/2wu43eS Biotechnology - http://amzn.to/2EZyqf9 Biology in Human Welfare https://amzn.to/4dPRZd7 Ecology https://amzn.to/3RwuOvF ____________________________________________ For business inquiries: abhibakore@gmail.com ___________________________________________ #HugoDeVries #MutationTheory #Saltation #EveningPrimrose #EvolutionNEET #Class12Biology #NeelaBakoreTutorials