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.
Let's look at this process, which is called photosynthesis. Living organisms such as humans breathe in oxygen and release carbon dioxide. Plants do just the opposite: they take in carbon dioxide and release oxygen. The carbon dioxide they take in is used to make sugar, which often times becomes our food. We can represent the process of photosynthesis in an equation: In this equation, we know that CO2 represents carbon dioxide, and H2O is water. Using the sun's energy and a pigment found in green leaves called chlorophyll, plants produce glucose, which is a form of sugar. And the O2 is the oxygen gas that is released.