Question

how does biological weathering occur?
due to physical factors such as freezing and thawing
plants, lichens, and mosses accelerating breakdown
by chemically breaking down rocks by gases

Explanation:

Biological weathering is the process where living organisms contribute to the breakdown of rocks. Plants, lichens, and mosses play a role in this. Lichens and mosses can grow on rocks and release chemicals that help break down the rock surface. Plants' roots can grow into cracks in rocks, and as the roots grow, they exert pressure, causing the rocks to break apart. This is different from physical weathering (like freezing - thawing which is a physical process) and chemical weathering by gases (which is more about non - biological chemical reactions).

Answer:

plants, lichens, and mosses accelerating breakdown