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Algae , mosses and ferns. Jimmy 6S 24. Algae. Protoctist Autotrophic Eukaryotic, simple and photosynthetic No roots, stems, leaves, and vascular tissues Possess cell wall Most contain chlorophyll and are green in color
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Algae , mosses and ferns Jimmy 6S 24
Algae • Protoctist • Autotrophic • Eukaryotic, simple and photosynthetic • No roots, stems, leaves, and vascular tissues • Possess cell wall • Most contain chlorophyll and are green in color • Some contain other photosynthetic pigments and are brown or red in color
Algae can be • unicellular • multi-cellular • colonies (cells aggregated) • and filamentous (cells arranged end to end) • The multi-cellular ones have an undifferentiated body called thallus
spirogyra • Un-branched filamentous green algae • Spirally coiled chloroplasts (increase surface area for absorbing light energy) • Mucilage (prevent desiccation and predation) • Two layers of cell wall, one is pectin and the other is cellulose
fucus • Large marine brown algae • Found in the inter-tidal zones of rocky seashores • The thallus consists holdfast, stipe and fronds • The whole body is covered by mucilage • Possess air bladders
frond stipe from wiki holdfast
habitats • Aquatic areas like fresh water, marine water • Terrestrial areas like moist surfaces of soil, rock and tree bark • Many algae are phytoplankton and suspended in water
Mosses • plant • Grow in shady and damp areas • Possess rhizoids, simple stems and leaves • No a vascular system and cuticle • No flowers and seeds • Leaves are like spirally arranged blades
Reproduction of mosses • Rely on water for reproduction • Possess capsules • Spores are released from capsules • The spores develop into a new plant under suitable environment • So the mosses can inhabit the terrestrial • Environment
Habitats of mosses • Grow in some moist environment • Absorb water and minerals directly through the body surfaces • Grow in dense colonies • Prevent soil erosion • Act as soil conditioner
Ferns • Terrestrial plants • growing in shady and humid places • Possess stems, leaves (fronds), adventitious roots and vascular bundles • Fronds are large, thin and delicate • No seeds, flowers and fruits
Special features of ferns • Presence of sporangium • A spore-bearing structure for reproduction • Form clusters, sori • Found on the lower surface of the fronds
Habitats and its adaptive features • Rocks, walls, fields, deserts, mountains • Slow-growing (low light density) • Fronds grow above the plant (spore dispersion) • Thicker cuticle and epidermal layer (reduce water loss) • With thicker and tougher fronds (ferns growing in exposed areas)
Epiphytic ferns • Plants growing on surface of other plants • Possess small but thick fronds • Fronds have thick cuticle and sunken stomata (reduce water loss) An epiphytic bromeliad