What is the primary source of energy for all ecosystems on Earth, except for the deep-sea hydrothermal ecosystem?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Solar radiation
Every ecosystem needs a steady supply of energy. Plants and photosynthetic bacteria capture the energy of sunlight and store it in food, and all other organisms depend on this food. So solar radiation drives almost every ecosystem on Earth. The one exception the book names is the deep sea hydro-thermal ecosystem, which lies far below the reach of sunlight.
NCERT Extract:
Energy Flow – “Except for the deep sea hydro-thermal ecosystem, sun is the only source of energy for all ecosystems on Earth. Of the incident solar radiation less than 50 per cent of it is photosynthetically active radiation (PAR). We know that plants and photosynthetic bacteria (autotrophs), fix Sun’s radiant energy to make food from simple inorganic materials.”