vin cycle. With this system, these plants can continue photosynthesis on hot days, even with their pores almost completely closed. A field of corn thus remains green on blistering days when neighboring plants wither, and crabgrass thrives in lawns browned by the summer sun. Cacti (Figure 14) also have developed ways to thrive in the harsh desert climate. They lack normal types of leaves which easily lose water by transportation. Photosynthesis occurs in the green stems where few stomata (Figure 15 & 16) are present in the cactus. Aquatic plants are another type of plant that is extremely well adapted to complete the process of photosynthesis. The giant kelp has gas filled bladders attached to the leaves to help bring them closer to the surface to absorb optimum light (Figure 17). Also, some types of algae have phycoerythrin, which is a pigment that collects the filtered blue-green light under water and uses it for photosynthesis [8]. This pigment gives the algae a brilliant red color (Figure 18). Bacteria (Figure 19) lack chloroplasts, and instead use structures called chromatophoresmembranes formed by numerous foldings of the plasma membrane, the membrane surrounding the fluid, or cytoplasm, that fills the cell [11]. The chromatophores hold thylakoids similar to plant thylakoids, which in some bacteria contain chlorophyll. For these bacteria, the process of photosynthesis is similar to that of plants, algae, and seaweed. Many of these chlorophyll-containing bacteria are abundant in oceans, lakes, and rivers, and the oxygen they release dissolves in the water and enables fish and other aquatic organisms to survive. Certain archaebacteria, members of a group of primitive bacteria-like organisms, carry out photosynthesis in a different manner. The mud-dwelling green sulfur and purple sulfur archaebacteria use hydrogen sulfide instead of water in photosynthesis [10]. These archaebacteria release sulfur rather than oxygen, ...
