What are the stomata and why does plants need them?

1 Answer
Mar 25, 2018

Stomata are openings present in epidermal cells of mainly leaves and younger stem. These are necessary as these mainly regulate transpiration.


Stomata are openings present in epidermal cells of leaves. The distribution of stoamta is determined by the habitat of plant. In plants exposed to bright sunlight, stomata are more on lower surface of leaf ( bifacial leaf ) as compared to that on upper surface. In plants growing in shady habitat, the stomata are equally distributed on both the surfaces ( isobilateral leaf ).

Each stoma is surrounded by two kidney-shaped gaurd cells . The changes in the turgidity of gaurd cell control opening and closing of stomata. Water loss from the surface of leaf, termed transpiration , mainly occurs trough leaves, though some transpiration occurs through general surface of leaf.

Besides transpiration , stomata also carry out gaseous exchange (intake of carbon dioxide and giving out of oxygen) occurring during photosynthesis.

Thus plants need stomata for the vital processes like transpiration and photosynthesis.