1. Describe the hydrologic cycle, and describe the difference between evaporation and evapo-transpiration.
The hydrologic cycle is the system by which water continuously circulates through the biosphere (p.394-5).
Evaporation is the process by which water changes from a liquid to a gas.
Transpiration is the transfer of water from plants leaves and stems into the atmosphere.
Evapo-transpiration is a combination of the two.
2. Discuss how human activity affects water quality according to our text.
According to the text, humans affect water quality by introducing waste. Waste that is contributed to water from humans includes agriculture (fertilizers, biocides and animal waste), industry, mining and municipalities and residences (p.399). This added waste eliminates organisms that live in that clean water.
3. At what point does the text say that substances released into water and air become pollutants?
The text states that substances released into water and air become pollutants when the water and air cannot cleanse itself. Air is polluted when it contains substances in sufficient concentrations to have a harmful effect on living things (p. 404).
4. Where are the five Great Garbage Patches located, and what are the problems associated with these garbage islands? Describe one.
The five Great Garbage Patches are located in the North and South Pacific Oceans, Indian Ocean, and the North and South Atlantic Oceans.
Problems associated with these garbage islands is that the plastics are not biodegradable and wildlife can also mistake the objects for food causing injury or death to the animal.
5. What steps have been taken by the U.S. federal government to control air and water pollution?
In 1963 the United States passed a Clean Air Act to establish national air-quality standards. In 1990 it passed a Clear Air Act, controlling the level of pollutants that could be released into the air. In 1972 the US passed a Clean Water Act which over saw the