Living Things in the Environment

A species of rabbit lives in a meadow where grass plants are readily available during summer months. The rabbits do not stray far from the meadow because the plants supply food and protection from predators. One summer, a fire destroys the plants in the meadow. As a result of the absence of plants in the meadow, the rabbit population will probably

• increase in size

• decrease in size

• reproduce more

A population of mice occupies a tree stump in a forest. During the last decade, there has been little change in the number of mice in the population. Which of the following would likely cause the number of mice to decrease quickly?

• a decrease in disease

• an increase in predators

• a decrease in competition for resources

What is an autotroph?

• Organism that makes its own energy

• Organism that eats other organisms for food & energy

• Organism that breaks down dead organisms

An isolated African canyon community in which cheetahs and leopards consume only impala antelopes is being observed. In a hypothetical scenario, the number of leopards increases in the canyon. Formulate a logical conclusion about the change that is MOST LIKELY to be the first to occur after the leopard population increases.

• The impala population will decrease.

• The cheetah population will increase.

• The impala population will remain the same.

An increase in pesticide use has resulted in a decrease in the local blue jay population. What is the BEST explanation for the decreased blue jay population?

• Blue jay food supply of bugs increased.

• Blue jay food supply of bugs decreased.

• Many blue jays moved into the area.

The table shows moose populations in Bullwinkle National Park, over a 35 year period. What could have been responsible for the decrease in the moose population in 1990?

• a disease epidemic

• a decrease of hunting

• an increase in the amount of food

Earthworms, fungi, and mushrooms are all considered:

• Decomposers

• Autotrophs

• Heterotrophs

The population of mice in a local forest ecosystem has recently died out due to disease. In the past, these mice were the main predators of the forest beetles.

What is the best prediction about what will happen to the beetles?

• The drop in the mouse population will lead to a drop in the beetle population.

• The drop in the mouse population will lead to no change in the beetle population.

• The drop in the mouse population will lead to an increase in the beetle population.

In natural ecosystems, the presence of predators lessens the effects of _________________ among the prey.

• competition

• infection

• reproduction

Which is NOT a limiting factor in the environment?

• money

• food

• shelter