Question

Student to attempt either option (A) or (B):
(A) Explain how the interaction between a fig tree and its tight one-to-one relationship with the pollinator species of wasp is one of the best examples of mutualism. 
OR 
(B) Correctly depict (also indicate the trophic level) and describe the ecological pyramid of number with 32 birds dependent on 20 insects feeding on one banyan tree.

Hint:

Mutualism involves reciprocal benefit. The fig-wasp relationship is highly specific. Ecological pyramids of number can be upright or inverted depending on the ecosystem.

Answer 1

(A) Step 1: Mutualism is an interaction where both species benefit from each other.
Step 2: In the case of fig tree and wasp:

• The fig tree is pollinated only by its specific species of wasp.
• The wasp lays eggs inside the fig fruits.
• The fig provides shelter and nourishment for the larvae.
• Both species are dependent on each other for survival and reproduction.

Step 3: This is a classic example of co-evolved mutualism.

OR

(B) Step 1: The ecological pyramid of number represents the number of organisms at each trophic level. In this case, the pyramid is upright. 
Step 2: Representation of the pyramid:

Trophic Level	Organisms and Number
Trophic Level 3 (Secondary Consumers)	Birds – 32
Trophic Level 2 (Primary Consumers)	Insects – 20
Trophic Level 1 (Producers)	One Banyan Tree – 1

Step 3:

• The number of organisms decreases from producers to top consumers.
• A single banyan tree supports many insects, which in turn are preyed upon by more birds.

Thus, this pyramid shows how energy flow supports different populations.