Saprophytes are fungi that feed on dead and decomposing organisms. they secrete enzymes that digest components of cell walls, such as cellulose and lignin. which statement explains why these fungi are an important part of the biogeochemical cycle? a) saprophytes perform gas exchange that assists the cellular activities of autotrophs. b) saprophytes extract minerals from living tissue to recycle them back into the soil. c) saprophytes transport nutrients through the xylem and phloem in autotrophs. d) saprophytes return organic material to the soil for use by living organisms.