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

A sphere of energy flow shows the amount of energy lost from one trophic level to the next.

Nitrogen can be used by plants as a nutrient when it is in the form(s) of ____.

Transpiration is the process by which _____.

One challenge of laboratory research is that ____.

The ____________________ occupies those parts of the atmosphere, hydrosphere, and geosphere where life is found.

Most of the phosphorus in the phosphorus cycle is in the form of ____, used by plants as a nutrient.

A(n) _____ contains groundwater that has collected in layers of rock, sand, and gravel.

Ecologists use computers to run____________________ to simulate ecosystems and study complex processes that cannot be adequately studied using field or laboratory research.

The ____ includes all of the water in all phases (solid, liquid, or gas) on or near the earth's surface.

Water contracts when it freezes, making ice more dense than liquid water.

Photosynthesis is performed by ____.

Which of the following best represents the process of photosynthesis?

A(n) ____________________ consists of populations of different species living in a particular place and potentially interacting with each other.

Oxygen accounts for about ____ of the air in the atmosphere.

Lightning is one of the natural mechanisms by which atmospheric nitrogen is converted to ammonia or ammonium ions.

The amount of carbon dioxide in the atmosphere is affected by the carbon cycle.

Clearly explain the distinction between Gross Primary Productivity (GPP) and Net Primary Productivity (NPP).

Organisms that cannot produce their own food and have to feed on other organisms are called ____________________.

Life on earth depends on the ____ of ____ energy from the sun.

A sequence of organisms, each of which serves as a source of nutrients or energy for the next, is called a(n) ____________________.