Biology Test Preparation Practice

    Interdependent Relationships In Ecosystems


    Base your answers to questions 4 on the data table below, which shows the estimated population of wolves in Minnesota from 1995 through 2002.

    scientific inquiry, data organization, plot and interpretation fig: lenv12014-examw_g14.png

    Directions: Using the information in the data table, construct a line graph on the grid, following the directions below.


    Base your answers to questions 12 on the graph below and on your knowledge of biology. The graph shows interactions of moose and wolf populations on Isle Royale.

    ecology, relationships among organisms fig: lenv12013-exam_g20.png


    Base your answers to questions 13 on the information below and on your knowledge of biology.

    Types of Predators

    When large predators, such as lions or wolves, are removed from a food web, smaller “mesopredators” step in to take their places, and the results may be severe. Mesopredators are usually smaller and more numerous than the larger “apex” predators that they replace. Some are also omnivores, eating plant and animal food sources, rather than eating the meat-only diet of the largest predators. Examples of mesopredators include coyotes, raccoons, and skunks.

    In 1874, General George Custer noted that there was an abundance of wolves, but few coyotes, in South Dakota. Today, there is an abundance of coyotes, but no wolves. The wolves were removed to protect domestic sheep, but now the coyotes are often responsible for attacking sheep and other animals. The cost of controlling mesopredators by human intervention can be very high, as mesopredators are very numerous and quickly “bounce back” after control efforts. Meanwhile, the number of apex predators that are endangered continues to increase.


    Base your answers to questions 14 on the chart below and on your knowledge of biology. The chart shows seasonal changes in an ecosystem and the overall carrying capacity of the ecosystem.

    ecology, organization of ecosystems  fig: lenv12016-examw_g17.png


    Base your answers to questions 15 on the information and graph below and on your knowledge of biology. The graph contains information about an ecosystem.

    The graph below shows the carrying capacities of an ecosystem for three different species, 1, 2, and 3, that inhabit an area and the actual population sizes of these three different species in the area.

    ecology, materials cycle through ecosystems fig: lenv62012-exam_w_g24.png