Ch. 15 (word) - LTCC Online

C. Most bacteria are beneficial or neutral to humans and to all life, and life probably began w/ bacteria. II. Early earth and the origin of life (Fig. 15.2) – life needed the build up of O2 (Fig. 15.3) Life began on a young earth. 3 billion yrs ago- earth bristles w/volcanoes, poisonous atmosphere; greenish mats of prokaryotes line shore ................
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