Read the passage and answer the following questions:

Apart from the deep-sea hydrothermal ecosystem, the primary source of energy for all ecosystems on Earth is the sun. However, only a portion of the incident solar radiation, less than 50 percent, is photosynthetically active radiation (PAR). Autotrophs, such as plants and photosynthetic bacteria, utilize this radiant energy to produce food from simple inorganic substances. Remarkably, plants can capture only 2-10 percent of the PAR, yet this small amount of energy sustains the entire living world. Understanding how solar energy, captured by plants, flows through different organisms within an ecosystem is crucial. In this unidirectional flow of energy, the sun nourishes the producers (often green plants), which serve as the foundation of the ecosystem. In terrestrial ecosystems, herbaceous and woody plants are the major producers, while in aquatic ecosystems, various species like phytoplankton, algae, and higher plants play this vital role. All other organisms, referred to as consumers or heterotrophs, depend on producers for their food requirements. Consumers can be classified based on their feeding habits. Those that directly consume producers, the plants, are called primary consumers. In contrast, if animals eat other animals that, in turn, feed on plants or their products, they are known as secondary consumers. Tertiary consumers, similarly, consume animals from the secondary consumer level. In summary, the entire ecosystem relies on the unidirectional flow of solar energy, starting from the sun to the producers (plants), and then passed on to the various levels of consumers, ensuring the sustenance of life within the ecosystem.

What percentage of the photosynthetically active radiation (PAR) is captured by plants?

2-10%

The correct answer is Option (2) -2-10%

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). Plants and photosynthetic bacteria (autotrophs), fix Sun’s radiant energy to make food from simple inorganic materials. Plants capture only 2-10 per cent of the PAR and this small amount of energy sustains the entire living world. So, it is very important to know how the solar energy captured by plants flows through different organisms of an ecosystem. 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.