Moss invades and establishes itself on bare rock, accumulating the beginnings of soil. after several years, enough soil has become established that grasses begin to grow where there was once bare rock. without the moss building up soil, the grasses would have had no chance. the establishment of the mosses on bare rock and eventual addition of grasses represents:

Me ! which of the following is an environmental concern of genetically modified foods? a) crops that are drought resistant are introduced providing food regardless of the unpredictable weather b) reduction cost of production for the crops c) an important ingredient may be introduced in a strain of rice for the poor who depend on rice as a primary food d) toxic substances produced as a pesticide may be consumed by unintended species