b) sile
1. The soil component which is comes from the weathering of rocks constitutes
a) the inorganic component of the soil
b) the organic component of the soil
c) not necessary for plant growth
d) none
2. Which of the following does not contribute to the chemical composition of
soils?
a) the chemical nature of underlying rocks
b) volcanic activity
c) rainfall
d) none
3. Constituents of soils which are easily leached by rain and taken up by plants are stored
a) in all parts of the soil
b) on the exchange sites of the organic and clay components
c) in the silicate fraction of the soil
d) only in the organic fraction of the soit
4. The particle size of which of the following the smallest?
a) sand
b) silt
c) clay
d) gravel
5. Soils containing a greater proportion of which of the following tends to drain quickly than the others?
a) sand
c) clay d) gravel
6. Living organisms in the soil
a) contribute to the organic component of the soil
b) do have no role in soil formation
c) facilitate the disintegration process of rocks in soil formation
d) a &c
7. The soil horizon which is rich in minerals is
a) A horizon b) B horizon c) Chorizon d) the O layer
8. What is the first step in pedogenesis?
a) disintegration of parent materials
b) formation of the parent material
c) decay of plant materials
d) formation of the soil horizons
9. Regolith is
a) bedrock
b) soil formed by the weathering of rocks
c) a layer of rock debris formed by the gradual weathering of bedrock
d) the organic soil component
10. The layer of soil from which the eluviation of clay, iron, and aluminum oxides takes place by leaching is
a) A horizon
b) B horizon
c) C horizon
d) E horizon​