Final answer:
A cell that uses organic carbon and energy from light is called a photoheterotroph. Photoautotrophs also use light but fix inorganic carbon dioxide, while chemoheterotrophs and chemoautotrophs utilize organic and inorganic compounds respectively for energy, without using light.
Step-by-step explanation:
A cell that uses an organic carbon source and obtains energy from light would be called a photoheterotroph. These organisms utilize light for energy but rely on organic carbon sources from other organisms for their carbon needs. The term 'photoheterotroph' combines 'photo-', indicating that light is the energy source, and 'heterotroph', meaning the carbon source is organic and derived externally.
While photoautotrophs also use light as an energy source, they differ from photoheterotrophs because they use carbon dioxide as their carbon source, fixing it into organic compounds through photosynthesis. This makes photoautotrophs like plants and cyanobacteria primary producers in ecosystems. In contrast, chemoheterotrophs and chemoautotrophs do not use light for energy; chemoheterotrophs acquire both their energy and carbon from organic molecules, whereas chemoautotrophs use inorganic compounds as an energy source and carbon dioxide for their carbon.