This happens when a detection is accomplished through heuristics. There is no such thing as a heuristic virus. As a technical concept, everything in malware detection is done via heuristics.
Photosynthesis is the process in which plants (also autotrphoic protists and some bacteria) use light energy, from the Sun, to make sugars and organic food molecules from CO2 and water (H2O). This process is essential for the formation of not only energy, but also for the formation of glucose for purposes of structure.
Photosynthesis makes the glucose that is used in cellular respiration to make ATP. The glucose is then turned back into carbon dioxide, which is used in photosynthesis. While water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.