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CHARACTERISTICS Eukaryotic cell Autotrophic nutrition (photosynthesis) Multicellular organisms. Reproduction: Asexual (spores or fragments ) Sexual (seeds) Interaction: movements of growth.
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Classification of plants Plants without seeds: Plants without flowers that reproduce trhough spores and live in wet environment to be able to reproduce. Plants with seeds: They have flowers that contain the reproductive organs and have seeds wich propagate better than spores. Spermatophytes
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EVOLUTION IN PLANTS WITHOUT SEEDS WITH SEEDS ( Spermatophyta) Mosses Ferns Gymnosperms Angiosperms (bare seeds) (fruits) Evolutionary time
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Plants without seeds Mosses No tissues or organs. They reproduce by spores formed in capsules. (Sporangium) Non-vascular (no xylem or phloem tissue) Without true roots, leaves or stems. With rhizoids. The surface must remain moist
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Plants without seeds Ferns They have roots, stem, underground stem (rhizome) and leaves (fronds) Spores are formed on the underside of the frond in sorus. They live in humid habitats, they need a lot of water to survive. The reproduction is complex. The cycle involves spores and gametes!!!!
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Fern
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Plants with seeds but no fruit GYMNOSPERMS Seeds are not enclosed in a fruit. Conifers are the most common gymnosperms. They are trees; they have thin and waterproof leaves. The majority are trees.The flowers are the cones that contain their reproductive structures. Unisexual. Female cones: larger than male cones. Central axis and sclaes arranged in a spiral shape around it. Each scale contains two ovules. Male cones: smaller and grow in clusters. The scales contain millions of pollen grains. A pine tree’s seed is called pine nut.
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Plants with both seeds and fruits. Angiosperms Most are deciduous trees. Flowers have calix and corolla. They can be unisexual or hermaphrodite. Seeds are developed into a fruit that comes form the fertilisation of an ovule. Ovules and pollen grains are produced in the stamen and carpels. Pollination is the transference of the pollen from the anther to the stigma. The fertilised ovule develops into a seed that contains an embryo (with food) and a seed coat. The ovary ripens into the fruit that contains the seeds
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Flower structure
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Seed structure
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Plant structure Organs: 1. Roots: to anchor the plant and to absorb water and mineral salts 2. Stem: to support leaves, flowers and fruits. It contains a system of vascular vessels that transport sap 1. Xylem: from roots to leaves 2. Phloem: from the leaves to everywhere 3. Leaves: with a waxy layer and stomata. Photosynthesis
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Leaf types
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