Excretion in Plants
Excretion occurs in plants and animals as they both have waste products to be removed from their bodies. Plants are less complex in structure than animals, and have their own means of excretion.
Plants eliminate some waste through diffusion. During the day, excess oxygen gas produced by photosynthesis is released through the stomata. Carbon dioxide produced by respiration is normally used up during photosynthesis. At night, however, as photosynthesis slows, carbon dioxide is not used up as fast as it is produced, and it is released as a waste product. Plants also produce oxygen as a by-product of photosynthesis. The oxygen that is not used for respiration is also excreted through the stomata.
Plants also eliminate waste by the accumulation of waste in the vacuoles of the aging leave cells. These leaves will eventually die and fall off, removing waste in the process. This process is called abscission.
In temperate countries, such as the UK and the USA, during autumn the leaves change to a bright array of colours. This is due to the storage of waste pigment in the leaves.
Have you ever noticed sticky, milky or oily substances being oozed from the bark of trees? These are excretory products and may be resins, gums, latex and or other excretory products. These products maybe poisonous, however many have found use in everyday life of humans, such as latex which is used to produce gloves and clothing.