Energy Flow in Ecosystem- Food Chain and Food Web MCQ

Quick Facts

Functions of Ecosystem: Energy Flow

Energy has been defined as the capacity to do work. Energy exists in two forms: potential and kinetic.
The source of energy required by all living organisms is the chemical energy of their food. The chemical energy is obtained by the conversion of the radiant energy of the sun.
Of the incident solar radiation less than 50 percent of it is photosynthetically active radiation (PAR).
Plants capture only 2-10 percent of the PAR and this small amount of energy sustains the entire living world.
All organisms are dependent for their food on producers, either directly or indirectly.
So, there is a unidirectional flow of energy from the sun to producers and then to consumers.
Ecosystems need a constant supply of energy to synthesise the molecules they require, to counteract the universal tendency toward increasing disorderliness.
Living organisms can use energy in two forms: radiant and fixed energy.
- Radiant energy is in the form of electromagnetic waves, such as light.
- Fixed energy is potential chemical energy bound in various organic substances which can be broken down in order to release their energy content.
Autotrophs can fix radiant energy utilizing inorganic substances to produce organic molecules.
Heterotrophs cannot obtain energy from abiotic sources but depend on energy-rich organic molecules synthesized by autotrophs.