Plant-Diversity-and-Classification--From-Bryophytes-to-Angiosperms (1).pptx

plant diversity

1. Plant Diversity and Classification: From Bryophytes to Angiosperms

2. Introduction to Plant Classification Plants are diverse organisms that can be classified based on key characteristics Main classification criteria: Presence of vascular tissue Presence of leaves and roots Method of reproduction (seeds vs. spores) Structural complexity

3. Vascular vs. Non-Vascular Plants Vascular plants: Have specialized tissue for water/nutrient transport Include xylem and phloem Non-vascular plants: Lack specialized conducting tissue Transport water through simple diffusion Usually small and grow close to the ground

4. Understanding Bryophytes First group of land plants Non-vascular plants Examples: mosses, liverworts, hornworts Characteristics: No true roots (have rhizoids) No true leaves Reproduce via spores

5. Life Cycle of Bryophytes Alternation of generations: Gametophyte (dominant phase) Sporophyte (dependent phase) Require water for reproduction Spore dispersal by wind

6. Introduction to Pteridophytes First vascular plants Examples: ferns, horsetails Key features: True roots present True leaves (fronds) No seeds (reproduce via spores)

7. Pteridophyte Characteristics Vascular tissue present Complex root system Large leaves for photosynthesis Independent sporophyte generation Prefer moist environments

8. Understanding Gymnosperms First seed-producing plants Examples: pines, spruces, cycads Key characteristics: Naked seeds (not enclosed in fruit) Usually evergreen Needle-like or scale-like leaves

9. Gymnosperm Reproduction Produce cones instead of flowers Male and female cones Wind pollination Seeds develop on surface of cone scales No fruit formation

10. Introduction to Angiosperms Most advanced and diverse plant group Flowering plants Two main classes: Monocotyledons Dicotyledons

11. Angiosperm Characteristics True roots, stems, and leaves Vascular tissue present Flowers for reproduction Seeds enclosed in fruits Most successful plant group

12. Flower Structure Main parts: Sepals Petals Stamens (male) Pistil (female) Adapted for various pollinators

13. Fruit Formation Process: Pollination Fertilization Ovary development Seed maturation Protects and aids seed dispersal

14. Types of Fruits Simple fruits (from single flower) Aggregate fruits (from multiple carpels) Multiple fruits (from multiple flowers) Examples from local plants: Apples, berries, citrus Compound fruits like pineapples

15. Seed Dispersal Methods Wind dispersal Animal dispersal Water dispersal Explosive mechanisms Importance in plant distribution

16. Evolutionary Timeline Bryophytes (oldest) → 470 million years ago Pteridophytes → 420 million years ago Gymnosperms → 305 million years ago Angiosperms → 125 million years ago

17. Ecological Importance Role in ecosystems: Oxygen production Habitat creation Food sources Soil stabilization

18. Local Plant Diversity Common local examples of each group Adaptation to local climate Seasonal changes Conservation importance

19. Comparative Analysis Evolution of features: Vascular tissue development Reproductive strategies Adaptation to land Structural complexity

20. Review and Summary Key differences between plant groups Evolutionary progression Importance of diversity Connection to local ecosystem Role in human society