Evolution of photosynthesis C photosynthesis is the oldest and most common form. C3 is a plant that uses the calvin cycle for the initial steps that incorporate CO2 into organic material. C4 is a plant that prefaces the calvin cycle with reactions that incorporate CO2 into four-carbon compounds. CAM is a plant that uses crassulacean acid metabolism, an adaptation for photosynthesis in arid conditions. C4 and CAM Plants have special adaptations that save water. The biochemical capacity to use water as the source for electrons in photosynthesis evolved in a common ancestor of extant cyanobacteria. The geological record indicates that this transforming event
What You Need (The Twilight Zone) What You Need (The Twilight Zone) "What You Need" is episode 12 of the American television anthology series "The Twilight Zone". It is based on the short story of the same name by Lewis Padgett (Henry Kuttner and C. L. Moore). Pedott , a peddler, has the curious ability to give people exactly what they need before they need it. He enters a coffee shop where he first gives a woman a vial of cleaner. Then he gives a down-on-his-luck ex-baseball player a bus ticket to Scranton, Pennsylvania. Moments later, the ball player receives a phone call at the cafe