What characterizes phototrophs?

Phototrophs are organisms that harness sunlight to produce energy. This process primarily involves photosynthesis, where light energy is converted into chemical energy, enabling these organisms to create their own food in the form of glucose. This ability to use sunlight as an energy source is a defining characteristic of phototrophs and distinguishes them from other types of organisms that rely on different methods for energy acquisition.

The focus on sunlight in the metabolic processes of phototrophs highlights their role in ecosystems as primary producers. By converting light energy into chemical energy, they form the base of the food chain and provide essential energy sources for other organisms, including herbivores and, subsequently, carnivores.

In contrast, organisms that obtain energy from chemical reactions or consume organic material are classified differently and are not considered phototrophs. Phototrophs specifically emphasize the use of light energy, making option B the correct choice.