In nature, energy flows in only one direction. Transfer of energy must occur in an ecosystem because all life needs energy to live, and only certain organisms can change solar energy into chemical energy. Producers are eaten by consumers that are, in turn, eaten by other consumers. Stable ecosystems must contain predators to help control the populations of consumers. Since ecosystems contain many predators, exterminating predators would require a massive effort that would wipe out predatory species from barnacles to blue whales. Without the population control provided by predators, some organisms would soon overpopulate.
Explain the phrase "only certain organisms can change solar energy into chemical energy," in the underlined portion of the first paragraph. In your answer be sure to identify:

1)the type of nutrition carried out by these organisms

2)the process being carried out in this type of nutrition

3)the organelles present in the cells of these organisms that are directly involved in changing solar energy into chemical energy