 
 <prompt> ```Why dem dey use C4 pathways? Based on di previous question, write one context wey go contain di answer. E fit be 1 - 20 sentences. Context:``` <response>: Plants dey produce some kain unique polymers like di polysaccharide molecules cellulose, pectin and xyloglucan from which di land plant cell wall dey build. Vascular land plants dey make lignin, a polymer wey dem use to strengthen di secondary cell walls of xylem tracheids and vessels to prevent dem from collapsing wen plant dey suck water through dem under water stress. Lignin dey also used for other cell types like sclerenchyma fibers wey dey provide structural support for plant and e dey a major part of wood. Sporopollenin na chemically resistant polymer wey dey for di outer cell walls of spores and pollen of land plants wey dey responsible for di survival of early land plant spores and di pollen of seed plants for di fossil record. E dey widely seen as a marker for di beginning of land plant evolution during di Ordovician period. Di concentration of carbon dioxide for di atmosphere today dey much lower pass wetin e be wen plants first come out for land during di Ordovician and Silurian periods. Many monocots like maize and di pineapple and some dicots like di Asteraceae don since independently evolve pathways like Crassulacean acid metabolism and di C4 carbon fixation pathway for photosynthesis wey avoid di losses wey dey come from photorespiration for di more common C3 carbon fixation pathway. These biochemical strategies dey unique to land plants. 