Nucleus is the largest organelle in the cell and contains all the cell's genetic information in the form of DNA. The presence of a nucleus is the primary factor that distinguishes eukaryotes from prokaryotes.
Like other succulent plants, most cacti<span> employ a special mechanism called "crassulacean acid metabolism" (CAM) as </span>part<span> of </span>photosynthesis<span>. Transpiration, during which carbon dioxide enters the plant and water escapes, </span>does<span> not </span>take place<span> during the day at the same time as </span>photosynthesis<span>, but instead </span>occurs<span> at night.</span>