1. In addition to the obvious membrane enclosing the DNA, what other structures differentiate the eukaryotes from prokaryotes? What environmental pressures most likely directed the evolution of these eukaryotic structures? 2. What data support the theory of endosymbiosis? What "common sense" observation refutes the theory of endosymbiosis? Propose an alternative theory by which eukaryotic cells evolved from prokaryotic ancestors.3. Scientific data suggest that humans infected with intestinal pathogens are more readily adapted to survive. How is this possible? What role do intestinal microbes play in human biology?
