Definition: A grassland biome is a terrestrial biome which includes, across its entire spatial extent, an unbroken layer of grasses (Gramineae), sedges (Cyperaceae) or rushes (Juncaceae).
Definition: the biochemical pathway a plant uses to gain carbon for growth and reproduction. Plants have evolved three photosynthetic pathways, each in response to distinct environmental conditions, resulting in differences in their ecological patterns of growth and distribution.
Definition: a photosynthetic process in some plants. It is the first step in extracting carbon from carbon dioxide to be able to use it in sugar and other biomolecules. It is one of three known processes for carbon fixation. The C4 in one of the names refers to the four-carbon molecule that is the first product of this type of carbon fixation.
