AP BIOLOGY

Detailed explanation-1: -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-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. A small proportion of this chemical energy is transformed directly into heat when compounds are broken down during respiration in plants.

Detailed explanation-3: -The energy of the sun is the original source of most of the energy found on earth. We get solar heat energy from the sun, and sunlight can also be used to produce electricity from solar (photovoltaic) cells.

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

Detailed explanation-5: -Only several types of alternative sources are not of solar origin. They are the tidal energy conditioned by gravitational attraction of the Moon, the nuclear energy accumulated by the universe many billions years ago, and the geothermal energy of the Earth generated during formation of the planet.