CBSE Class 10 Answered

The fundamental energy source for most of the environment is the sun. Photoautotrophs capture the sun’s energy and use it to make organic compounds through photosynthesis. The process of photosynthesis transforms carbon dioxide and water into simple carbohydrates. Photoautotrophs are often also called primary producers because they establish the basis for most other production; they create organic material from inorganic, or non-living, sources.

Most of the photoautotrophs in the marine environment are the small in size and are the marine algae and cyanobacteria. They are vital to our planet's productivity since they are at the base of the marine food web. The consumers in food webs are called heterotrophs and they consume the organic material made by the autotrophs. Heterotrophs cannot make their own food so they are dependent on the autotrophs for survival.