Question

cengage | mindtap
unit 4: quiz
assignment: unit 4: quiz
questions ch04.04

1. the three layers of a normal soil profile are ______.

a. root zone, topsoil, and subsoil
b. topsoil, subsoil, and root zone
c. soil, subsoil, and bedrock
d. sand, silt, and clay

Explanation:

A normal soil profile consists of three main layers: the topsoil (which is the upper layer with organic matter and is part of the root zone), the subsoil (below topsoil with less organic matter), and the bedrock (the bottom layer, also sometimes considered with the soil and subsoil layers as soil, subsoil, bedrock). Option c (soil, subsoil, and bedrock) correctly identifies the three layers of a soil profile. Option a has incorrect ordering (root zone is related to topsoil, not a separate layer in the profile structure here), option b has root zone which is not a distinct layer of the soil profile structure, and option d lists soil particle types, not profile layers.

Answer:

c. soil, subsoil, and bedrock