Exam 45: Community and Ecosystem Ecology

What is the correct sequence of organisms if a community is going through secondary succession? a.grasses establish themselves in the community B.shrubs establish themselves in the community C.soil formation occurs D.trees establish themselves in the community

Excluding humans,which group of organisms is most likely to change the abiotic factors within an ecosystem?

________ occurs when one living organism feeds on another.

Approximately what percentage of the energy in one trophic level is incorporated into the next trophic level?

There are several species of grain beetles that live on dry meal and do considerable damage to stored grain.In an experiment,a dozen jars of dry meal are set up and fifty individuals of each species,both males and females,are added to each jar.The food supply is not quite sufficient to last for six months and the size of the jar is adequate so that wastes do not become toxic.Most likely,examination of the jars in six months will find

Which of the following statements about the value of the nitrogen cycle to an ecosystem is NOT true?

Which of the following statements about ecological pyramids is true?

The frequent change in HIV surface proteins is a type of

Ecologist Robert MacArthur observed that five species of similar warblers coexisted on spruce trees because they

Over two decades ago in the People's Republic of China,it was noticed that songbirds were eating rice and millet drying on the grain floors.Since there were large numbers of people to feed,and the population was very near to carrying capacity,it was proposed that the songbird population should be reduced in order to preserve more grain.However,the songbirds also ate a larger number of insects that fed on the rice and millet when it was young.Draw a food web including the above items,indicating energy flow in the direction of the arrows,and representing the general proportion of energy consumed by the breadth of each arrow.State briefly why this decision was disastrous.

Which of the following is (are)correct in a predator-prey cycle?

Hurricanes and other severe precipitation events have started becoming weaker and less intense as a result of climate change.

Which of the following statements about parasitism is NOT true?

_____ is the interaction between two species as both attempt to use the same environmental resources that are in limited supply.

All food chains begin with a photosynthetic producer.

Which of the following associations between organism and nutrient source is incorrect?

Is it possible that the carbon atoms in your body may have once made up the living tissues of another person or animal in earlier times? This is

An ecosystem contains

Chemical cycling may involve all but which of the following?

The actual conditions under which an organism exists in nature constitute its