The biotic potential and the population size modified by the environmental resistance determine the _________________________.

Which of the following resulted in an orogeny in eastern North America?

A) collision with an island arc
B) collision with a land mass called Avalonia
C) a continental collision
D) all of these
E) a and b only

What is responsible for the formation of prairie potholes? 

A)  meteor impacts 
B)  Earthquakes 
C)  retreating glaciers 
D)  volcanic craters

______________________________ occurs when wastes are made into new products of the original type.

Which of the following is a significant impact of burning biomass? 

A)  It does not cause water pollution. 
B)  It releases more carbon dioxide per ton burned than coal does. 
C)  It can cause soil erosion, water pollution, and loss of wildlife habitat. 
D)  It releases more air pollution per unit of energy produced than does uncontrolled burning of coal.

Which type of crust has the greater thickness?

A) continental
B) oceanic

Which statement applies to natural ecosystems? 

A)  They are subject to continuous invasion by pathogens and weeds. 
B)  They are usually capable of self-maintenance and self-renewal. 
C)  They have most of their biomass in one species. 
D)  They require applications of pesticides.

One reason for the decline in Canada's salmon stocks is that salmon fishing has ____________________ dimensions.

The observed loss of ozone above Antarctica is called the _________________________.

Which chronic disease would NOT likely be worsened by ozone in photochemical smog? 

A)  asthma 
B)  diabetes 
C)  bronchitis 
D)  emphysema