A look at micro organisms, where the team talks about how they work, their need for water, the role of the freezer and refrigerator, different kinds of bacteria - good and bad, and the inevitability of food rotting - nature's way. Living systems dependence on other systems are described, while reproduction and heredity, populations and ecosystems, nature of chemical processes are explored. Chemical change, nitrogen cycle, producers, consumers and decomposers, technological design, science in personal health, and science and technology in society.