Question

Topsoil contains the following

• A. Humus and living organisms only
• B. Humus and soil particles only
• C. Humus, living organisms and plants
• D. Humus, living organisms and soil particles

Answer 1

The correct option is D

Humus, living organisms and soil particles

The correct option is D.

Explanation of correct option:

1. The topmost layer of the Earth’s crust primarily comprising rock particles and organic minerals, which support life is the soil.
2. The upper or A-horizon or the topsoil comprises the humus and the majority of the litter living organisms. It also comprises the leaching zone, via which the dissolved substances leak downward.
3. small plant roots are present in the topsoil.
4. The B-horizon or the second layer is also known as the sub-soil comprises the minerals.
5. The C-horizon or the third layer of the soil comprises the unconsolidated parent material.
6. The D-horizon or the last layer constitutes unmodified parent material or rock.

Final answer: The topsoil comprises the humus, living organisms, and soil particles.