Chloroflexi are typically filamentous (they look like microscopic strings), and can move about through bacterial gliding. They are facultatively aerobic (they can survive with oxygen or without it), but do not produce oxygen in the process of producing energy from light, or phototrophy. Additionally Chloroflexi have a different method of phototrophy (photoheterotrophy) than true photosynthetic bacteria. Phylogenetic analysis (looking at DNA) indicates that they had a separate origin.