• Question: How do plants breathe?

    Asked by demilouise123 to James, Marcus, Martin, Rob, Suzanne on 19 Mar 2012.
    • Photo: Suzanne McEndoo

      Suzanne McEndoo answered on 19 Mar 2012:

      Plants “breathe” in the opposite way to us (technically it’s not breathing, it’s called respiration). We take in oxygen to burn sugars and release CO2. Plants take in CO2, make sugars and then release oxygen. (Although, in the dark, plants go the opposite direction, taking in oxygen and releasing CO2.)

      I think plants take in air mostly through their leaves. Then the leaves use photosynthesis to make food for the plant, hence their green colour.

      This BBC site has some useful info on the subject. http://www.bbc.co.uk/schools/ks3bitesize/science/organisms_behaviour_health/food_chains/revise4.shtml

    • Photo: James Boone

      James Boone answered on 19 Mar 2012:

      Suzanne is right, and the tiny holes in the leaves that allow the intake of gases such as Carbon Dioxide are called stomata.

    • Photo: Marcus Gallagher-Jones

      Marcus Gallagher-Jones answered on 20 Mar 2012:

      Ooh sorry guys you can’t technically call what plants do breathing. Breathing must be a tidal process where a volume of gas is moved in or out of a set of lungs. The process in plants is entirely passive and so can’t be considered breathing. It s still pretty interesting however.

      Stomata are intrinsically linked to the system that moves water around plants. When there is a lot water available the cells of stomata (called guard cells) swell and create an opening allowing carbon dioxide to enter and oxygen to leave by passive diffusion. This ensures that plants only uptake CO2 when they need it, both CO2 and water are needed for photosynthesis.

Comments