spirogyra (from diversity of plants)....

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1. Diversity of plants Topic : SPIROGYRA

2. spirogyra TAXONOMIC POSITION Division chlorophyta Class chlorophyceae Order zygnemales Family zygnemaceae Genus spirogyra

3. introduction Largest and common 300 species Water silk or pond scum Grows abundantly in spring Plant body Long green filament Hold fast rhizoidal outgrowth

4. structure 1-CELL WALL two layers Outer (cellulose) Inner(pectin) 2-CYTOPLASM Thin lining b/w cell wall and larger vacuole Contain different organelles

5. 3-NUCLEUS Prominent Suspended by thin cytoplasm strands 4-CHLOROPLAST Ribbon shaped and spirally arranged Contain Pyrenoids PIGMENTS Chlorophyll Xanthophyll Carotenes

6. Reproduction vegetative method(mostly) asexual method(only in some species) sexual method(in unfavorable conditions) 1-VEGETATIVE METHOD Fragmentation

7. 2-sexual method CONJUGATION two filaments glued papillate formation common walls dissolved(conjugation tube) protoplast round off to form isogametes Anisogamy Diploid zygote zygospore germination Factors : Low nitrogen supply High light intensity

8. TYPES OF CONJUGATION 1-SCLARIFORM CONJUGATION Most common type Between opposite filaments

9. 2- LATERAL CONJUGATION in a single filament Conjugation canal

10. zygospore STRUCTURE Three layered Spherical(diploid) Red in color GERMINATION Zygospore Meiosis Germ tube Development in filament