Exam 20: Communities and Ecosystems

Please refer to the following art to answer the following question(s). -Refer to the following figure. If there were an additional trophic level that consisted of organisms that prey on snakes,about how much energy would be available to organisms at that trophic level?

Approximately what percentage of the visible light that reaches Earth's producers is converted to chemical energy?

The atmosphere is approximately 80% ______ gas.

A regional assemblage of interacting ecosystems is a ______.

In order to assess the species diversity of a community,you would need to know the number of different species present as well as ______.

______ convert nitrogen from a form that can be assimilated by plants to N₂.

Please refer to the following art to answer the following question(s). -The figure below shows the growth curves of two populations of Paramecium,P.aurelia and P.caudatum.From the data,we can conclude that ______.

The single greatest threat to biodiversity comes from ______.

Plants can utilize the ______ form of nitrogen.

Several years ago I was crossing the border from Canada to the United States and I had a bag of Washington State apples with me. The customs officer at the border would not let me take the apples with me into the United States (and I really hated the idea of getting rid of a bag of perfectly good apples). Why did the customs officer refuse to allow me to cross the border with my apples?

Bears eat berries,humans,and large fish; large fish eat smaller fish and insects; humans eat bears,large fish,and berries; Venus flytraps eat insects.The scenario described here is an example of ______.

The rate at which an ecosystem's producers convert solar energy to chemical energy stored in biomass is called ______.

With regard to nutrient pollution in aquatic ecosystems,when is the worst time to apply fertilizer to your lawn?

Organisms that consume producers are ______.

Please refer to the following art to answer the following question(s). -Refer to the figure above. This photo represents ______ community(ies).

Movement corridors are ______.

Species found in only one place on Earth are called ______ species.

Which of these organisms convert atmospheric nitrogen gas to a form that can be utilized by plants?

In the food chain grass → antelope → human → lion,the antelope is

Which type of ecosystem has low production but nonetheless contributes a large proportion of Earth's total net primary production?