Explanation
The correct answer is (a) Plants and some bacteria capable of producing their own food.
Producers in an ecosystem are organisms that are capable of producing their own food through photosynthesis or chemosynthesis. They convert sunlight, water, and carbon dioxide into organic compounds that serve as a source of energy for other organisms in the ecosystem.
Plants, including trees, grasses, and algae, are primary examples of producers in most terrestrial and aquatic ecosystems. They use photosynthesis to produce food using sunlight, water, and carbon dioxide. Some bacteria, such as cyanobacteria, are also capable of photosynthesis and can function as producers.
Animals, including fish, are consumers in an ecosystem as they obtain their energy by consuming other organisms. Human beings are also consumers, as they rely on consuming plants or animals for their energy and nutritional needs.
Therefore, the correct answer is (a) Plants and some bacteria capable of producing their own food.