Exam 3: Ecosystems: What Are They and How Do They Work

If grass stores 1,000 energy units received from the sun, the ecological efficiency of the ecosystem is 10%, and the trophic levels are grass → cow → human, how many units of energy does the human receive of the original 1,000 units?

What is a primary link between photosynthesis and aerobic respiration?

What term describes groups of different species living together in a particular place with a potential for interacting with one another?

Organisms that convert simple inorganic compounds into nutrients, without sunlight, are called ____________________ .

Use the accompanying figure to answer the following question(s). Why is heat shown as being lost to the environment?

The oceans of the earth cover approximately what percentage of the earth's surface?

Aerobic respiration requires ____.

The most fundamental structural and functional units of life are ____.

Methane, CO₂, and water vapor make up about 30% of the earth's troposphere.

In the plains states of the U.S. (Kansas, Nebraska, Texas, etc.), agricultural withdrawal of groundwater from aquifers has greatly exceeded the supply. Explain why removal of this resource will have long-term effects on the hydrologic cycle.

Which terrestrial ecosystem or life zone produces the highest net primary productivity per year?

____________________ refers to how fast producers can make the chemical energy that is stored in their tissues and that is potentially available to other organisms (consumers)in an ecosystem.

Each trophic level in a food chain or food web contains a certain amount of organic matter, called ____.

The hydrologic cycle is a way nature renews water quality.

Decomposers are mainly bacteria and ____________________.

Use the accompanying figure to answer the following question(s). Letter D, at the base of the pyramid given above, represents what group of organisms?

The hydrosphere is the earth's intensely hot core, thick mantle composed mostly of rock, and thin outer crust.

The three major processes in the water cycle are ____________________, ____________________, and ____________________.

Because carbon makes up such a small amount of the earth's atmosphere, even a small change, caused by nature or by humans, affects the earth's climate.

Much of the earth's sulfur is stored in