Transpiration

    Cards (33)

    • The stem, root and leaves form an organ system that transports substances into, around and out of a plant.
    • The need for transport in plants is highlighted by transpiration.
    • Transpiration is the loss of water from leaves by evaporation through the stomata.
    • Factors affecting transpiration include environmental factors such as temperature and humidity.
    • Transpiration can be investigated using potometers, which measure water uptake.
    • The distribution of stomata and guard cells can be investigated as part of transpiration research.
    • When the plant opens its stomata to let in carbon dioxide, water on the surface of the cells of the spongy mesophyll close spongy mesophyll.
    • The plant tissue in a leaf which has loosely packed cells and air spaces between them to allow gas exchange is called the spongy mesophyll.
    • The plant tissue containing closely packed cells in the upper layer of a leaf is called the palisade mesophyll.
    • Evaporation is the process in which a liquid changes state and turns into a gas.
    • Diffusion is the process where particles spread out from a region of higher concentration to a region of lower concentration.
    • Water is drawn from the cells in the xylem to replace that which has been lost from the leaves.
    • Water molecules inside the xylem cells are strongly attracted to each other due to strong cohesion between the molecules because of hydrogen bonding.
    • Hydrogen bonding is a relatively strong intermolecular attractive force that develops between a hydrogen atom and an electronegative atom.
    • Hydrogen bonding between water molecules involves an attractive force between a hydrogen atom in one water molecule and the oxygen atom in another.
    • As water travels through the xylem in the stem and leaf, it is being replaced by water taken up by the roots.
    • Non-communicable diseases are also part of animal organisation.
    • Soil water moves into the root hair cell by osmosis and across the root cortex to the xylem.
    • Minerals are necessary for both plant and animal health.
    • Only five per cent of the water taken up by the plant is used for photosynthesis, but it does have its purposes: it provides the water for photosynthesis and transports mineral ions.
    • Water enters the root hair cells by osmosis because soil water has a higher water potential than the cytoplasm of the root hair cell.
    • Language options for the BBC include English, Cymraeg, Gaeilge, and Gàidhlig.
    • A continuous column of water is pulled up the stem in the transpiration stream by evaporation from the leaves.
    • Minerals enter by active transport.
    • Animal organisation also includes digestion.
    • Factors affecting transpiration include the need for transport in plants.
    • Sample exam questions for organisation include topics such as Biology, Bitesize revision podcasts, and Personalise your Bitesize.
    • Jobs that use Biology include the BBC Earth, Save My Exams, Quizlet, Tassomai, and Headsqueeze.
    • Algae subsumed within plants and some bacteria are also photosynthetic.
    • Water uptake and transport across the root occur through root hairs, which are single-celled extensions of epidermal cells.
    • Animal organisation includes gaseous exchange systems.
    • Transpiration is an unavoidable consequence of photosynthesis.
    • Animal organisation also includes transport systems.