Plant+Structures+and+Functions

Plants structures and functions Parenchyma: The most abundant kind of plant cell, found in plant tissues, thin flexible cell walls. Collenchyma: Long cells with unevenly thickened cell walls, they can stretch as the cell grows while providing strength and support, arranged in tube like strands or cylinders (like the strands in celery) Sclerenchyma: Thick walls, once mature they usually die, give support for plant. Dermal tissue: Also called the epidermis, make of flattened cells that cover all parts of the plant, and protects plant. Stomata: Openings in the leaves that control the exchange of gases, found on the green stems of leaves. Guard cells: Control the opening and closing of stomata. Trichomes: Hairlike structures that make leaf and steam appear fuzzy, this helps keep predators away. Vascular Tissues: Dissolves minerals, food and water are transported through these. Xylem: Made of tubular cells that moves water and dissolved minerals from roots to the rest of the plant. Tracheids: Tubular cells that are tapered at each end. Vessel elements: Tubular cells that transport water through the plant. Phloem: Tubular cells that bring things down to the roots. Companion cells: Nucleated cells that help transport sugars to the roots. Ground Tissue: Made up of parenchyma cells, also has collenchymas and sclerenchyma cells. The function is photosynthesis storage and support. Meristematic tissues: Produce new cells here and have actively dividing cells. Apical Meristems: Found near the tips of the roots and stems, allow roots and stems to increase. Vascular cambium: Produces new Xylem and Phloem cells. Cork cambium: Makes cells with tough cell walls. Roots: Plant organs that anchor a plant into the ground, absorb water, and dissolve minerals. The structure of the roots: Small hairs that come off to increase surface area, absorb water, oxygen and dissolve minerals. Cortex: Involved in transportation of water and dissolved minerals to vascular tissues. Endodermis: Layer of cells that have water proof cell walls, they are around the vascular tissues. Paracycle: Lateral roots come off of this. Root growth: two areas of rapidly dividing cells, helps the roots increase in length. Root cap: A protective layer on the tip of the root. Steam: Above ground part of the plant that supports leaves and flowers, vascular tissues that transport water and dissolve minerals from the roots and leaves. Internal structure - Vascular tissues: Arranged in bundles or circular arrangements. Woody stems: Many trees have these stems; they get thicker as they age. This structure helps them grow in height. Stems transport materials: Water, sugars, and other compounds. Sink: Any portion of the plant that stores sugar. Translocation: Movement of materials in the vascular tissues of a plant. Leaves: Photosynthesis is the primary function. Leaf Variation: The shape of the leaf helps it attract sun and the different shapes help different plants. Petiole: Stalk that joins the leaf and stem together. Leaf Structure: Mezophyll: Tissue where photosynthesis takes place. Transpiration: Loss of water through the stomata. Venation patterns: The pattern the veins form on the leaves. Leaf modifications: some leaves have other adaptations other than photosynthesis; like catching water or creating an irritant when crushed. Plant Hormones: Regulate growth and development. Auxins cause stem elongation: Auxins: Promote cell elongation. Gibberellins promote growth: Gibberellins: Cause the plant to grow taller. Cytokinins stimulate cell division: Cytoknins: Stimulate mitosis and cell division. Ethylene gas promotes ripening: Ethylene: Simple gas made of carbon and hydrogen, produced by fruits. Plant Responses: Plants respond to their environment. Tropic responses in plants: Tropism: Plants response to external sources. Nastic Responses in Plants: Nastic Movements: when the plants response is not dependent on the direction of the stimulous.
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