Zoomed leafs picture
Added: 06/19/2011 by bee
In botany, a leaf is an above-ground plant organ specialized for the process of photosynthesis. Leaves are typically flat (laminar) and thin which evolved as a means to maximise the surface area directly exposed to light. Furthermore the internal organisation of leaves has evolved to maximise exposure of the photosynthetic organelles, the chloroplasts, to light and to increase the absorption of carbon dioxide, all of which assist photosynthesis.