Published on August 14, 2007
Plant Parts: Plant Parts Flowers, Roots, Stems and Leaves Flowers: Flowers Flower Parts: Flower Parts Petal - Petals are used to attract insects into the flower, they may have guidelines on them and be scented. Stigma - Is covered in a sticky substance that the pollen grains will adhere to. Style - The style raises the stigma away from the Ovary to decrease the likelihood of pollen contamination. It varies in length. Ovary - This protects the ovule and once fertilization has taken place it will become the fruit. Ovule - The Ovule is like the egg in animals and once fertilization has taken place will become the seed. Flower Parts: Flower Parts Receptacle - This is the flower's attachment to the stalk and in some cases becomes part of the fruit after fertilization e.g. strawberry. Flower stalk - Gives support to the flower and elevates the flower for the insects. Nectary - This is where a sugary solution called nectar is held to attract insects. Sepal - Sepals protect the flower whilst the flower is developing from a bud. Filament This is the stalk of the Anther Flower Parts: Flower Parts Anther - The Anthers contain pollen sacs. The sacs release pollen on to the outside of the anthers that brush against insects on entering the flowers. The pollen once deposited on the insect is transferred to the stigma of another flower or the same flower. The ovule is then able to be fertilized. Filament – the stalk that supports the anther Stamen – the filament and anther Pedicle – the stalk on which a flower is produced Roots: Roots Roots: Roots Epidermis. A single layer of flattened cells at the surface. When first formed, epidermal cells have extensions — the root hairs — which greatly increase the surface area available for the uptake of nutrients from the soil. The photo below shows the root hairs in the region of differentiation of a germinating radish seed. Cortex. A band of parenchyma cells that develops beneath the epidermis. It stores food. Its inner surface is bounded by a single layer of cells, the Endodermis. Roots: Roots Stele Pericycle - the outer boundary of the stele. Secondary roots branch from it. Xylem - arranged in bundles in a spoke like fashion Phloem - alternates with xylem Cambium - In older parts of the root, another meristem forms between the xylem and phloem. Mitosis in the cambium produces new 'secondary xylem' to the inside and secondary phloem to the outside. Parts of the leaves and stem: Parts of the leaves and stem Parts of the leaves and stem: Parts of the leaves and stem Leaf Blade: Wide flattened area of leaf for concentrating sunlight on photosynthetic cells. Petiole: Short stem that attaches leaf to main stem or branch. Veins: Vascular bundles within leaf for transport. Node: Growth region of stem where leaves or new branches arise. Auxiliary bud: Baby leaf or stem (next years growth). Simple Leaves: Simple Leaves Compound Leaves: Compound Leaves Internal Structure of Leaves: Internal Structure of Leaves Internal Structure: Internal Structure a) Cuticle: Waxy layer water proofing upper leaves. b) Upper epidermis: Upper layer of cells. No chloroplasts. Protection. c) Palisade Mesophyll: Tightly packed upper layer of chloroplast containing cells. d) Spongy Mesophyll: Lower layer of chloroplast containing cells. Air spaces around them. e) Lower Epidermis: Lower external layer of cells in leaf. Internal Structure: Internal Structure f) Vascular Bundle: Bundle of many vessels (xylem and phloem) for transport. g) Xylem: Living vascular system carrying water andamp; minerals throughout plant. h) Phloem: Living vascular system carrying dissolved sugars and organic compounds throughout plant. i) Guard Cells: 2 cells surrounding stomata that control rate of gas andamp; water exchange. j) Stomata: Opening between guard cells for gas andamp; water exchange.