In an ecosystem, the vertical distribution of different species occupying different levels is called.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Stratification
Option (1) Seral stage — Incorrect. A seral stage is one of the communities that replace each other in time during ecological succession, not a layering in space.
Option (2) Stratification — Correct. In a forest, trees form the top layer, shrubs the second and herbs and grasses the bottom layer.
Option (3) Trophic level — Incorrect. A trophic level is an organism's place in a food chain (producer, herbivore, carnivore), not its height.
Option (4) Standing crop — Incorrect. Standing crop is the mass of living material at a trophic level at a particular time.
Note: A similar question was also asked in CUET (UG) 2026 on 21-05-2026 (Slot 2), on 21-05-2026 (Slot 1) and on 18-05-2026 (Slot 1), in CUET (UG) 2025 on 29-05-2025 (Slot 1), and in CUET (UG) 2022 on 23-08-2022 (Slot 3).
NCERT Extract:
Ecosystem – Structure and Function – “… Interaction of biotic and abiotic components result in a physical structure that is characteristic for each type of ecosystem. Identification and enumeration of plant and animal species of an ecosystem gives its species composition. Vertical distribution of different species occupying different levels is called stratification. For example, trees occupy top vertical strata or layer of a forest, shrubs the second and herbs and grasses occupy the bottom layers.”