Chapter 21

A lake or pond receives runoff containing a large amount of chemical fertilizer.  Which of the following may occur MOST immediately after runoff?

• algal bloom
• algae death and decomposer overpopulation
• recycling of organic compounds
• drop in carbon dioxide levels

Why was DDT found to be hazardous over longer periods of time?

• it was a natural insecticide
• it decomposed rapidly
• it built up in consumers instead of decomposing
• it killed herbivores instantly

A construction company buries its trash in an area outside a construction site.  Which of the following is MOST likely to decompose quickly?

• wood
• nails
• fiberglass shingles
• cement bricks

Which of the following is NOT a goal of conservation?

• managing natural resources
• introducing non-native species into new environments
• protecting habitats and wildlife
• preserving biodiversity

Human activities can affect biodiversity, but so can natural events.  Which of the following is an example of a natural event that can decrease biodiversity?

• lichens and moss form soil as a part of primary succession
• birds migrate from Canada to South America
• hunters kill deer during hunting season
• a tornado knocks down trees in a forest

Which of these would be the most probable effect of increased use of CFCs?

• the ozone layer would disappear suddenly

• the ozone holes would shrink

• the ozone holes would grow

• there would be no change in the ozone layer

Which of the following is an example of how human efforts have decreased biodiversity?

• re-introducing endangered species into their natural habitats

• establishing National Forests that cannot be developed for commercial use

• strip mining to obtain valuable natural resources from underneath the earth's surface

• recycling and reusing plastic and paper so that they do not enter landfills

Which of the following is NOT a consequence of clearing rainforests?

• increase in global atmospheric oxygen

• loss of potential medicinal plants

• disruption of the carbon cycle

• extinction of tropical rainforest species

Which of the following is an example of how human activities have increased biodiversity?

• clear cutting tropical rainforests

• strip mining

• draining wetlands

• protecting natural habitats

Which event could cause primary succession to begin?

• a forest fire

• a severe storm

• abandonment of farm land

• volcanic eruption