QUESTION 1. Which parts of the geosphere are not included in the lithosphere?
the mantle and core
tectonic plates and faults
soil and bedrock
the crust and underlying rock layers

QUESTION 2. In a California woodland, a mistletoe plant gets its nutrition from live oaks, thus weakening the oaks. This relationship between the two species is an example of __________.
microorganism
commensalism
parasitism
mutualism

QUESTION 3. Which is not a general characteristic of populations?
They consist of all the species in a defined area.
They interact with other populations in an ecosystem.
They are subject to limiting factors such as food supply and predators.
They grow and decline over time.

QUESTION 4. What benefit do nitrogen-fixing organisms provide in an ecosystem?
They eat organisms that contain large amounts of nitrogen compounds.
They release nitrogen compounds into the air.
They turn atmospheric nitrogen into organic nitrogen compounds.
They convert nitrate to gaseous nitrogen.

QUESTION 5. Which scientist became famous for telling the world about the environmental harm caused by DDT?
Charles Darwin
Thomas Malthus
Rachel Carlson
Milutin Milankovitch

QUESTION 6. Which example describes migration caused by overcrowding?
Wolves follow caribou herds south to their seasonal pastures.
Hordes of rats flee a city when their numbers exceed the carrying capacity.
When crops fail, farmers move to cities to find factory work.
The range of Joshua trees moves north as temperature in their old range rises.

QUESTION 7. Which is a key difference between an ecosystem and a biome?
A biome contains fewer species than an ecosystem.
An ecosystem is larger than a biome.
The boundaries of an ecosystem change, while those of a biome do not.
Biome refers to all ecosystems sharing a similar climate and similar dominant plants and animals.

QUESTION 8. Why is the metric system more scientific than the English system?
The English system was based on human traits, while the metric system was founded on physical constants.
The English system is older than the metric system, so it does not apply to as many situations.
The English system is only used in English-speaking countries.
The English system must be converted to the metric system using conversion factors.

QUESTION 9. Which American environmental catastrophe most closely resembles the Great Smog of 1952 in London, England?
the "death" of Lake Erie in the 1970s
the Love Canal disaster in New York state in 1977
the air pollution disaster in Donora, Pennsylvania, in 1948
the Exxon Valdez oil spill in 1989
What causes acid rain?
reactions between industrial or automotive emissions and water vapor
a combination of smoke, fog, and water
agricultural chemicals running off into waterways
chlorofluorocarbons (CFCs) reacting with ultraviolet light and ozone

QUESTION 10. Which is not a harmful effect of loss of biodiversity?
Loss of predators means an increase in pest populations.
The hole in the ozone increases.
Water purification is hindered.
Soil formation is impaired.

QUESTION 11. What does biomass measure?
the number of organisms of different species in an ecosystem
the total number of links in all the food chains in a food web
the total mass of all the dry matter of all the organisms in an ecosystem
the rate at which an ecosystem's producers manufacture chemical energy

QUESTION 12. While climbing a mountain, you pass through a coniferous forest at 1,000 m and tundra at 5,000 m. How can the same mountain contain both ecosystems?
More sunlight reaches the top of the mountain.
Abiotic factors change with increasing elevation.
The middle of the mountain receives more rainfall.
Pine cones cannot reach the mountaintop because of downward winds.

QUESTION 13. What is an independent variable in a scientific experiment?
a variable that is measured in an experiment
a variable that scientists can manipulate to observe its effects
a variable that does not change during the course of the experiment
a variable that responds to the dependent variable