The correct option is 1 only
Explanation
Biological weathering involves the contribution of living organisms-such as plants, animals, and microorganisms-to the disintegration (mechanical) and decomposition (chemical) of rock materials. It acts as a bridge between physical and chemical weathering processes.
Statement-wise Analysis
- Statement 1 is Correct: Burrowing and wedging by organisms such as earthworms, termites, and rodents loosen the soil and rock material. This activity facilitates the penetration of moisture and air into the subsurface and exposes new surfaces to chemical attack, thereby accelerating weathering.
- Statement 2 is Incorrect: Decaying plant and animal matter leads to the production of humic, carbonic, and other organic acids. These acids do not prevent but rather enhance the decay and solubility of minerals in the rock, promoting chemical weathering.
- Statement 3 is Incorrect: Plant roots growing into cracks and crevices of rocks exert tremendous mechanical pressure on the surrounding earth materials. This pressure widens the cracks and mechanically breaks the rocks apart, a process often referred to as root wedging.
Key Takeaway
Biological weathering encompasses both mechanical disruption (e.g., root pressure, burrowing) and chemical decomposition (e.g., release of organic acids and humic acids) of geological materials.