Ans. Green plants and certain types of bacteria are able to convert the inorganic matter into biomass by using energy from solar radiation or by chemical energy. The primary producers are the first to come in connection with the food chain and thus they are called the primary producers, known as autotrophs.Two major types of primary producers are phototrophs and chemotrophs. Phototrophs are those who use the energy from the sun, to convert carbon dioxide into carbohydrates. This process is called photosynthesis.