Mrs. palmer held up a plant with its roots attached during a science lesson. she passed around a sample of the soil that the plant was growing in. she said that plant roots had grown down easily in this type of soil. this type of soil is also a mixture of sand, silt, and clay. what type of soil is mrs. plamer describing to her class? a) humus b) loam c) subsoil d) topsoil (this is for science)