NEET BIOLOGY

Detailed explanation-1: -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-2: -The sun is called the ultimate source of energy because: It is the primary source of energy for the earth. With the help of solar energy, all green plants(producers) produce food by the process of photosynthesis. In turn, animals eat plants and use that same chemical energy for all their activities.

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.