Definition: Gravel is an environmental material which is composed of pieces of rock that are at least two millimeters (2mm) in its largest dimension and no more than 75 millimeters.
Definition: one of three metabolic pathways for carbon fixation in photosynthesis, along with C4 and CAM. This process converts carbon dioxide and ribulose bisphosphate (RuBP, a 5-carbon sugar) into 3-phosphoglycerate through the following reaction:\r\n\r\nCO2 + H2O + RuBP → (2) 3-phosphoglycerate\r\n\r\nThis reaction occurs in all plants as the first step of the Calvin–Benson cycle.
Definition: A terrestrial plant is a plant that grows on or in or from land. Other types of plants are aquatic (living in water), epiphytic (living on trees) and lithophytic (living in or on rocks)
