[Campbell Biology P.855] Based on Figure 37.2 and the accompanying text, which statement cor... | Practice Question

Based on Figure 37.2 and the accompanying text, which statement correctly describes the characteristics of soil horizons?

  • A: The A horizon is primarily composed of unweathered parent material.
  • B: The B horizon contains more organic matter and is more weathered than the A horizon.
  • C: The C horizon is composed mainly of partially broken-down rock and serves as the 'parent' material for minerals.
  • D: All soil horizons are equally important for direct plant growth.

Explanation

Figure 37.2's description of the C horizon states: 'The C horizon is composed mainly of partially broken-down rock. Some of the rock served as 'parent' material for minerals that later helped form the upper horizons.' This directly matches option C.