Question

Student to attempt either option (A) or (B).
(A) Identify the type of pyramid given below and write two identifying features of such a pyramid: 

OR 
(B) 
(i) Construct an ideal pyramid of energy when 10,00,000 Joules of sunlight is available. 
(ii) Mention the energy obtained by the fourth level of this pyramid.} 
 

Hint:

The pyramid of energy is always upright because energy transfer between trophic levels follows the 10\% rule, with significant energy loss as heat at each step.

Answer 1

(A):
Step 1: The pyramid shown is an upright pyramid of energy, as it narrows progressively from the base (producers) to the top (higher trophic levels). 
Step 2: Two identifying features are: (i) It always has a broad base representing the energy at the producer level, and (ii) Energy decreases at each successive trophic level due to the 10% energy transfer rule, reflecting energy loss as heat. 
OR 
(B): 
Step 1: For (i), an ideal pyramid of energy with 10,00,000 J of sunlight (producers) follows the 10% rule. Primary consumers get 10% of 10,00,000 J = 1,00,000 J; secondary consumers get 10% of 1,00,000 J = 10,000 J; tertiary consumers (fourth level) get 10% of 10,000 J = 1,000 J. Thus, the pyramid is: Producers: 10,00,000 J, Primary Consumers: 1,00,000 J, Secondary Consumers: 10,000 J, Tertiary Consumers: 1,000 J. 
Step 2: For (ii), the energy at the fourth level (tertiary consumers) is 1,000 J. 
Thus, (A) identifies an upright pyramid of energy with its features, and (B) constructs the pyramid and specifies the fourth level’s energy as 1,000 J.