Review: Ecosystems

A plant is placed in a closed terrarium exposed only to sunlight with snails and soil decomposers. What must happen for the carbon cycle to continue in this terrarium?

• all organisms must continue to exchange gases

• the snails must double their production of carbon dioxide

• the plant must produce carbon dioxide at a faster rate

• the decomposers must begin to produce oxygen

In nature, which type of behavior causes animals to produce aggressive displays and sounds?

• imprinting

• territoriality

• conditioning

• habituation

What will most likely occur if the population of the world continues to increase at predicted rates?

• there will be an increase in biodiversity as a result of improvements in technology

• there will be more rapid depletion of natural resources

• the human race will rapidly become extinct

• all human diseases will be eliminated

What will most likely happen if a nonnative species is introduced into a stable ecosystem?

• the native species will change their diet, and the ecosystem will remain stable

• the native species will move to another area, and the ecosystem will remain stable

• the native species will have to compete for resources with the nonnative species, and the ecosystem will become unbalanced

• the native species will share their food with the introduced species, and the ecosystem will become unbalanced

Which statement best explains how sweating during exercise maintains homeostasis?

• it regulates mineral concentrations in cells

• it regulates body temperature

• it maintains water balance

• it maintains sugar levels

Which statement best explains why animals are considered heterotrophic?

• they are able to produce food through the process of photosynthesis

• they are able to produce food through the process of respiration

• they are able to obtain nutrients by decomposing plant and animal tissue

• they are able to obtain nutrients by consuming other organisms or their products

In some ecosystems, wolves have been eliminated due to their threats to humans. How can the reintroduction of wolves benefit the ecosystem?

• it can eliminate weak animals from a prey population, thereby decreasing competition for natural resources

• it can eliminate the most fit animals among the prey population, which will cause an increase in birthrates of the prey

• it can cause the prey population to migrate to other areas, resulting in more fit prey

• it can cause the prey population to better blend in with the environment

What will most likely be the result as humans move into new areas, forests are clear cut, and housing developments are built?

• global temperatures will decrease because trees are removed

• many organisms will lose their homes because their habitats have been destroyed

• better sanitation in the area will reduce the amount of pollution

• the rainfall in the area will increase because there will be increased runoff

What activity most contributes to the depletion of the ozone layer?

• burning fossil fuels

• release of CFCs

• deforestation

• overuse of fertilizers

Which will most likely result in a negative growth rate in the human population of a country?

• the death rate is higher than the birth rate

• the birth rate is higher than the death rate

• the country has improved economic conditions

• the country has made improvements in sanitation