Discuss the course objectives, the textbook to be used, and supplementary readings. Derive a definition of the environment through a series of questions. List and categorize as many factors which comprise our understanding of what the environment entails. Factors include animals, plants, soil, streams, rivers, and oceans. Other factors mentioned include types of biomes, fish, sewage, pollutants, and populations. Unseeable factors also enter into the definition, such as heat, light, and sound. From the list, derive a working definition that the environment is everything around us, what we can and cannot see. It involves the natural world as well as factors produced by humans. Discuss the term extinction, and briefly list reasons some species have become extinct or are dying off. Look at human activities such as water and air pollution caused by fertilizer runoff and carbon fuel burning. Natural factors of predator and prey relationships also can lead to extinction.