In the nature, which of the following is/are most likely to be found surviving on a surface without soil? Select the correct answer using the code given below

Answer: (c) 2 and 3

Lichens and mosses are the pioneers of bare rock.

Statement by statement

1. ✗ NO Ferns need soil or humus for their true roots.

2. ✓ YES Lichens grow on bare rock and start soil formation.

3. ✓ YES Mosses have no true roots; they grow on rocks, walls and bark.

4. ✗ NO Mushrooms need organic matter (soil, dung, wood) to feed on.

The idea

Lichens and mosses have no true roots, so they do not need soil. They cling to a bare surface with fine threads and take water and minerals straight from rain, dew and dust. A fern has real roots and a mushroom feeds on dead organic matter; both need something to grow in.

Bare rock → Lichens settle; their acids slowly break the rock surface → Dust and dead lichen form a thin film → Mosses grow on it and hold water → Soil builds up → ferns and grasses can follow

The trap

Ferns grow on tree trunks and walls, so they tempt. They still need humus in cracks.

Also know

Because they are first to arrive, lichens and mosses are called pioneer species.