Question

Energy transfer from one trophic level to another, in a food chain, is

• A. 0.05
• B. 0.1
• C. 0.15
• D. 20%.

Hint:

In the ecosystem, the primary producers depend on solar energy, the secondary consumers on the primary consumer, and the tertiary consumers on the secondary consumers. 

Answer 1

The Correct Option is B

Energy flow in an ecosystem is always unidirectional. Only 10% of the gross productivity of producers is trapped by herbivores for their bodybuilding. 

• Herbivores are eaten by carnivores.
• 10% of the herbivore productivity only is used for raising the productivity of primary carnivores.
• The rest is consumed in ingestion, respiration, maintenance of body heat and other activities.
• Higher carnivores similarly are able to retain only 10% of the energy present in primary carnivores.

This is called the 10% law. It was given by Lindemahn in 1942. The percentage of transfer of energy from one trophic level to another trophic level is 10% or 0.1.

Hence, the correct option is B) 0.1.

Answer 2

In the ecosystem, the primary producers depend on solar energy, the secondary consumers on the primary consumer, and the tertiary consumers on the secondary consumers. These are the five trophic levels of the ecosystem.

Complete Step-by-step answer:

All the organisms at all trophic levels produce energy as they consume food.

• The food is converted into energy which is passed onto the next trophic-level organisms when consumed as food. 
• During this process, energy is lost on passing on through each trophic level in the ecosystem.
• The energy that is transferred from one trophic level to another is around 10% and the left-out energy is lost in the metabolic process of food processing in the form of heat. 
• Therefore, the highest energy is acquired by the primary produces and then it decreases by 10% at each trophic level and the tertiary consumers have the lowest energy transferred from the upper trophic levels. 
• The energy passes from one trophic level to another when organic molecules from the body of an organism are eaten by another organism.
• The energy transfer is inefficient as not all the organisms at lower trophic levels are consumed as food sources, some molecules are not digestible by predators while some molecules are used in cellular respiration instead of being stored as biomass.

Hence, the correct answer is option (B).