Question

1. Construct an ideal pyramid of energy when 10,00,000 Joules of sunlight is available.
2. Mention the energy obtained by the fourth level of this pyramid.

Answer 1

i. About 1% of the 10,00,000 J of available sunlight is used by plants for photosynthesis, which means they consume about 10,000 joules of energy.

Herbivores, the primary consumers, would obtain roughly 10% of plant energy: 10% of 10,000 J = 1,000 J of energy at the primary consumers: 

About 10% of the energy from main consumers would go to secondary consumers, who are herbivore-eating carnivores:

Energy at secondary consumers = 10% of 1,000 J = 100 J

About 10% of the energy from secondary consumers would go to tertiary consumers, or carnivores that consume other carnivores:

Energy at tertiary consumers = 10% of 100 J = 10 J

ii. 10 joules of energy are obtained by the fourth level (tertiary consumers) of this pyramid.