2.8.2 Review Questions

While on a trip to Peru, Carlos saw that a mountainside had been terraced by the ancient Inca Indians. The Incas had terraced the side of the mountain to grow food.



Which other purpose did the terracing of the mountain serve?

• It provided a transportation system.

• It encouraged wild plant growth.

• It helped control erosion.

• It prevented flooding.

In some lakes, excessive blooms of algae appear when human activity causes degradation of water quality resulting in conditions more favorable for algae growth. Which human activity primarily causes this problem?

• mining

• farming

• transportation

• manufacturing

Which would be the best way to reduce the environmental impact of conventional agricultural practices?

• decrease fertilizer usage

• increase pesticide use

• decrease crop rotation

• increase use of nonnative species

On the edge of many deserts, there is a delicate area with abundant vegetation. Sometimes cattle are allowed to graze in these areas. The hooves of the cattle compact the topsoil making it less absorbent. Which environmental concern is most likely to happen at the edge of the desert when cattle graze there?

• nutrient depletion

• erosion

• atmospheric heating

• groundwater contamination

A lake has been used for more than a century to irrigate crops. How has this practice most likely affected this resource?

• It decreased the salt content of the water.

• It increased the evaporation rate of the water.

• It increased the number of fish in the lake.

• It decreased the volume of the lake.

Which of the following is the greatest source of wild fish for human populations?

• oceans

• ponds

• lakes

• rivers

Nitrogen is a nutrient needed by plants for growth. Nitrogen is naturally cycled into the soil where it is rapidly absorbed by plants. What would a farmer MOST likely do to replenish nitrogen that was depleted from the soil?

• use water that is enhanced with phosphates

• add fertilizer to the soil to provide a source of nitrogen

• use genetically altered crops that fix their own nitrogen

• add bacteria to the soil in order for the crop to grow stronger roots

Corn is widely being used in the United States to make ethanol for use in automobile fuel. How might the overproduction of corn negatively affect the environment?

• decreasing soil fertility

• decreasing oil transportation

• increasing the greenhouse effect

• increasing carbon dioxide emissions

Farmers use fertilizer on their crops to increase crop yield. How does the fertilizer affect plants and animals in nearby lakes and streams?

• Fertilizer directly kills fish and plant life in lakes and streams.

• Fertilizer leads to the growth of oxygen-depleting organisms.

• Fertilizer that becomes airborne pollutes the air around aquatic plants

• Fertilizer improves crops which draws animals away from the lakes and streams

Which change would best aid a farmer in making the transition from conventional farming techniques to more sustainable farming techniques?

• reduce the ratio of essential elements in the fertilizer

• irrigate crops using well water

• rotate the types of crops grown

• plant only genetically modified crops