(07.04 LC) Primary treatment of wastewater includes
adding chlorine to disinfect water before it is discharged
implementing UV light to disinfect large solids that float to the top
introducing bacteria to the sewage to break down inorganic matter
using large- and small-holed screens to remove coarse solids

Number and variety of living organisms includes genetic, species, and ecological types

The is an estimate of the fewest number of organisms a population needs to avoid extinction. this measurement will most if the number of offspring each female in the population produces increases. if the population's this measurement will most likely increase. 1 population density, minimum viable population, carrying capacity 2 decrease, be unaffected, increase 3 death rate increase, dead rate decrease

Natural selection changes allele frequencies because some survive and reproduce more successfully than others.