AP BIOLOGY

Detailed explanation-1: -3.1 The Sun is the major source of energy for organisms and the ecosystems of which they are a part. Producers such as plants, algae, and cyanobacteria use the energy from sunlight to make organic matter from carbon dioxide and water. This establishes the beginning of energy flow through almost all food webs.

Detailed explanation-2: -The vast majority of energy that exists in food webs originates from the sun and is converted (transformed) into chemical energy by the process of photosynthesis in plants.

Detailed explanation-3: -The Sun is the only source of energy for all ecosystems on Earth except for deep sea hydro-thermal ecosystem. In deep sea hydro-thermal ecosystem, sunlight cannot penetrate and hence chemical deposits and hydrothermal fluids are the source of energy for the organisms habitat in this ecoystem.

Detailed explanation-4: -Energy Production In most ecosystems, the ultimate source of all energy is the sun.