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

The troposphere and stratosphere are layers of the ____________________.

Carbon is extremely important because ____.

Net primary productivity (NPP) is the rate at which producers use photosynthesis to produce and store chemical energy minus ____.

In the Sonoran desert of the southwestern United States, scientists observed that population clusters of a small cactus were pronounced around nests of desert woodrats. Given this spatial relationship, they began to think the woodrat was connected to the seeding of these cactus plants.  After years of counting and observing woodrat nests and nearby cactus plants, scientists collected woodrat droppings for laboratory analysis to determine whether they contained cactus seeds. They also excluded woodrats from several other areas without cactus plants, then collected woodrat droppings and added those to half of these areas to examine whether the droppings were associated with the growth of new population clusters of the cactus. Scientists then programmed the data they had collected into a computer. A computer program enabled them to predict that increases in the woodrat population would result in corresponding increases in the cactus population, and likewise, a decrease in the number of woodrats would signal an impending decrease in cactus. - The transport of woodrat dropping to other areas to compare them with areas lacking droppings could be described as ____.

The process in which organisms, such as yeasts, break down organic molecules without the presence of oxygen is called ____________________.

Because the earth does not get significant inputs of matter from space, its essentially fixed supply of nutrients must continually be recycled to support life.

Water exists as a liquid over a wide range of temperatures because of the lack of attractive forces between its molecules.

Aerobic respiration produces carbon dioxide and water, whereas fermentation produces a range of products such as ethyl alcohol and hydrogen sulfide.

The oceans contain about ____ of the earth's water.

Ozone, a gas that filters out harmful ultraviolet (UV) radiation, is found in the ____.

Organisms that consume wastes and remains of plants and animals are ____.

Aerobic respiration is the process by which cells use oxygen to produce energy that they can use to fuel life processes.

As a primary consumer, a deer is part of the second trophic level.

The hydrologic cycle collects, purifies, and distributes the earth's fixed supply of water.

Given the nature of the carbon cycle, it is possible that a single atom of carbon that is in your skin could have once been part of your own great grandmother, or even a dinosaur.

Geographic Information System (GIS) software allows scientists to ____.

Water-soluble wastes are not a significant pollution problem because liquid water cannot dissolve as many compounds as most other liquids.

Water has the ability to filter out wavelengths of the sun's ultraviolet radiation that would harm some aquatic organisms.

Why is it that many top predators such as lions, tigers, bears, and wolves have extremely large territories and are relatively rare compared with primary consumers and producers?

The most common gas in the atmosphere is ____.