Donna is measuring rainfall over a large elevation gradient in the Cascade Mountains of Oregon. As she walks up the west side, she notices that rainfall increases and that when she reaches the top and walks down the east side, it is much drier. This is because:

a. dry air from the equator flows east at this latitude, dropping moisture on the west side.

b. wet air from the tropical equator flows east at this latitude, dropping moisture on the west, and then becomes dry by the time it reaches the eastern side.

c. air is flowing from the west and drops moisture as it rises and cools, then absorbs moisture from the land as it descends and warms.

d. warm air from 30° latitudes picks up moisture as it travels to 60° north, then drops this moisture as it cools.

e. the rain-shadow effect means that cool, moist air drops rainfall as it warms with a rise in elevation.

A lake affected by high levels of artificial eutrophication will have:

a. high nutrient levels, large phytoplankton populations, and low oxygen levels at depth.

b. high level, nutrients, low phytoplankton levels, and high oxygen levels in surface waters.

c. low nutrient levels, large phytoplankton populations, and low oxygen levels at depth.

d. low nutrient levels, low phytoplankton populations, and high oxygen levels at depth.

e. low nutrient levels, large zooplankton populations, and low phytoplankton levels.

An ecosystem includes a ________ of organisms and the _______ with which they interact.

The carbon that helps make up the living world moves into it by means of organisms that perform _______. Carbon then returns to the soil and atmosphere through means of the _______of organic material by the organisms called _______ and _______.

Almost all the nitrogen that enters the living world by natural means does so through the actions of _______. Nitrogen is then returned to the atmosphere by the actions of _______.

All the organisms at the first trophic level perform _______ and thus are referred to as _______. Any organism that feeds solely on first-trophic-level organisms would have to be a (choose one) carnivore/herbivore/omnivore.

All material produced by living things is capable of being broken down into its inorganic components by the class of living things called _______. This material is thus said to be _______.

There are fewer predator than prey animals due to drastic reductions of _______ at each _______.

Ozone is a gas composed entirely of the element _______ that reaches its greatest density in the layer of the atmosphere known as the _______ and that has the effect of keeping _______ from reaching Earth’s surface.

Most of the energetic short-wave radiation from the sun is transformed into _______, which can be trapped by greenhouse gases such as _______ and ________.

Global warming is certain to produce a _____ in global sea levels and a(n) _______ in precipitation in the United States.