Definition: A montane grassland biome is a grassland biome which occurs in regions elevated above sea level and which has community structure determined by elevation-dependent environmental conditions.
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.