Gas Exchange

• Gas Exchange in Plants

  • Plants obtain the gases through their leaves; they require oxygen for respiration and CO2 for photosynthesis; the gases diffuse into intracellular spaces through the stomata.
• Gas Exchange in Aquatic Plants

  • Lilypads have leaves that float giving them ready access to the air.
  • Mangroves have pneumatophores, also known as aerial roots, that grow above water surfaces.
• Gas Exchange in Plants

  • Stems - the hard stems of plants and trees have lenticels that allow the gaseous exchange of respiratory gases between air and living cells.
  • Root - plant roots take oxygen from the air that is present in between the particles of the soil.
• Gas Exchange System in Animals

  • Skin System - worms and amphibians use their moist body surface to breathe in oxygen.
  • Gills System - fish and other aquatic animals use gills to take up the dissolved oxygen from the water; the gills are thin tissue filaments.
  • Tracheal System - insects use their tracheae to facilitate gas exchange; it consists of air tubes called spiracles.