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
Ghetto Day/What I Need Picnic'." This sampling was also praised by Fred DeUar of "High Fidelity News and Record Review", who stated it was done "in the cause of better-class '90s pop." "Billboard" called the track "a languid, liquid sketch of a lazy city afternoon" and stated "it gets the nod as [the album's] likeliest knockout contender." Ron Wynn from AllMusic declared "What I Need" one of the album's best. "Billboard" Larry Flick labelled it a "floor-filler" and an "upbeat rouser." Another reviewer from the same publication thought "What I Need" was one of the hits to be had from "Storyteller". "Vibe" magazine stated