Find the odd one out with reference to terrestrial ecosystem:

The correct answer is Option (3) → Wetland

Ecosystems are grouped as terrestrial (forest, grassland, desert) and aquatic (pond, lake, wetland, river, estuary).

Option (1) Forest — Terrestrial.

Option (2) Grassland — Terrestrial.

Option (3) Wetland — The odd one out. NCERT lists the wetland among the aquatic ecosystems.

Option (4) Desert — Terrestrial.

NCERT Extract:
Ecosystem–structure and Function – “… Many ecologists regard the entire biosphere as a global ecosystem, as a composite of all local ecosystems on Earth. Since this system is too much big and complex to be studied at one time, it is convenient to divide it into two basic categories, namely terrestrial and aquatic. Forest, grassland and desert are some examples of terrestrial ecosystems; pond, lake, wetland, river and estuary are some examples of aquatic ecosystems.”