EEMB 3 Study Guide - Spring 2019, Comprehensive Final Exam Notes - Dna, Oxygen, Bacteria
8 May 2019
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About 2 x 10^9 species in existence. 70% are in prokaryotic realm (bacteria & archaea) 10 x more bacteria cell than human cells. Help to digest food, fight pathogens, provide vitamins. Less than 1% of microbial world is actually pathogenic to us. 71% of earth surface is occupied by ocean. 97. 5% salt water, 2. 5% fresh water (ice caps) Total volume is 1. 4 x 10^7 km^3. 300 x more space for life than on land or fresh water. Psii: acquire the majority of their nutrients through passive exchange with their environment. Earth is a living entity because of its ability to maintain homeostasis & have its biosphere regulate climate & atmosphere at an optimum. James lovelock to identify life in other solar systems, look for atmospheres that are in chemical disequilibrium. Venus: 96. 5% co2, 3. 5% n2, 0% o2. Earth: 0. 03% co2, 72% n2, 21% o2. Very violent place lots of hydrothermal activity.
