Exam 28: Community Interactions

In a stable ecosystem, the number of predators is greater than the number of prey.

The rocks and weather that influence succession are examples of factors.

The biotic portion of an ecosystem includes the plants, animals, and water.

After a forested area such as a national forest is clear- cut, what type of succession occurs?

In the rain forests of Panama, scientists found a colony of tree- dwelling black ants where some individuals had red abdomens. When examined, the scientists determined that the ants with red abdomens were infected with roundworm eggs. Birds would prey on these ants, mistaking their red bellies for berries. In the interactions among the tree- dwelling black ants, the roundworms, and the birds, the roundworms are the

The bright coloration of toxic tree frogs is an example of .

In a process called coevolution, two species exert natural selection pressures on each other.

Succession after a disturbance such as forest harvest or a landslide is referred to as succession.

Invasive species outcompete native species because they lack predators and have high reproductive rates.

What is the relationship between an ecosystem and a community?

The sea dragon in the illustration displays

Most bacteria can reproduce very quickly, so their populations increase rapidly. Describe the evolutionary process that prevents most human- disease- causing bacterial parasites from causing the human population to become extinct.

Trees often produce secondary chemicals to deter herbivores from feeding on their leaves; in turn, many herbivores have developed ways of avoiding or detoxifying these chemicals. This is an example of

What effect does coevolution most likely have on niche overlap?

A bat pollinates a plant while obtaining nectar from it. This behavior is an example of .

The succession shown in the illustration is

Two species of buttercup are found in a field in North Dakota, and they tend to flower at approximately the same time in early spring. When some ecology students decided to conduct an experiment in community dynamics, they selectively removed one species from the field by hand- picking all emergent plants. The remaining species showed a significant increase in its population size during the next season. This study demonstrated

An example of is when birds feed on parasitic insects that they pick off the skin of large animals such as elephants or bison.

Plants called legumes have chambers in their roots that house nitrogen- fixing bacteria. Nitrogen- fixing bacteria get both a place to live and energy while supplying nitrogen to a plant. What is this ecological relationship called?

When all vegetation is removed from a site by human activity or by natural forces such as volcanic activity, species are the first to recolonize the site.