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  1. How are cells structured? Learn about the size and function of plant and animal cells for GCSE Combined Science, AQA.

    • Plant and Animal Cells

      There are many different types of cells in animals. Each...

    • Video

      Cell structure - AQA Video. Organisms are made up of cells....

  2. May 9, 2023 · 9 May 2023. Did this video help you? Structure of the Leaf. Plant leaves have complex structures with layers of different tissues containing specially adapted cells. The table below describes the different structures in a leaf and their functions. Leaf Structures Table. Diagram showing the cross-section of a leaf.

  3. How are cells structured? Learn about the size and function of plant and animal cells for GCSE Biology, AQA.

    • Cuticle
    • Upper Epidermis
    • Palisade Mesophyll Layer
    • Spongy Mesophyll Layer
    • Lower Epidermis

    It is the waxy layer of the leaf secreted by the epidermis, a thin layer of leaf present just below the cuticle. It performs the following functions: 1. Preventing excessive water loss from the leaves through transpiration 2. Controlling the exchange of gases such as dioxide and oxygen from the leaf surface Giving mechanical support and thus preven...

    It is a thin layer of cells below the cuticle. Mostly they are devoid of chloroplasts and thus do not perform photosynthesis. The upper epidermis performs the following functions: 1. Preventing excessive water loss from the leaves through transpiration 2. Allowing sunlight to pass through the spaces between the cells and thus helping to initiate ph...

    It is found just below the upper epidermis and is thus also called the upper leaf cells. They consist of columnar cells arranged vertically beside each other, much like the columns of a building. The columnar cells are tightly packed to maximize the absorption of sunlight. Sometimes it can consist of several layers of cells, particularly in environ...

    This layer is found below the palisade layer. Also called the lower leaf cells, the spongy layer consists of irregularly shaped cells consisting of the vascular tissues – xylemand phloem, forming the vascular bundles. The vascular tissues are surrounded by parenchymal pith and collenchymas. The cells contain minute pores called stomata (Singular: s...

    It is located on the bottom side of the leaves below the spongy mesophyll layer of cells. Stomata are essential structures in the lower epidermis. There may be up to one million stomata per square centimeter. Each stoma is flanked by kidney-shaped epidermal cells called guard cells. The guard cells control the opening and closing of stoma based on ...

    • Cell Wall. It is the outermost, protective layer of a plant cell having a thickness of 20-80 nm. Cell walls are made up of carbohydrates such as cellulose, hemicellulose, and pectin and a complex organic polymer called lignin.
    • Plastids. They are double membrane-bound organelles that have their own genetic material. Plastids are mainly of three types: a) Chloroplasts: Found in the green parts of a plant and algae that contain the photosynthetic pigment, chlorophyll.
    • Central Vacuole. It is the large vesicle that make up almost 30 to 80% of the total plant cell volume. The central vacuole is often the largest organelle in the cell that is filled with fluid, ions, enzymes, and other molecules.
    • Cell Membrane or Plasma Membrane. It is a thin, biological membrane having a thickness of 7.5-10 nm that separates the interior of the cell from the outside environment.
  4. Dec 2, 2014 · The leaf is the organ in a plant specially adapted for photosynthesis. You need to understand the structure of the tissues in a leaf together with their functions. Upper Epidermis: this is the tissue on the upper surface of the leaf.

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  6. Video. Test. Pages. Plant cells. Most life on Earth depends upon plants for energy. Plants capture light from the sun and use it to build up chemical stores of energy. This is called...