7 UNIT 8

A student sets up the investigation shown below. What does the movement of colored water across the sand into the water best model?

• Evaporation of surface water

• Infiltration of groundwater

• Condensation of water vapor

• Pollution of surface water

What is a watershed, and what are the effects of human activity on surface water and groundwater in a watershed?

Farmers can best reduce negative effects on the water quality of nearby streams and lakes by planting crops that —

• produce less oxygen

• produce less carbon dioxide

• need less fertilizer

• need less solar energy

A person changes the oil in his car and discards the old oil into a hole in the ground. What is one possible effect of this action?

• The small amount of oil will create a barrier between it and the groundwater.

• The small amount of oil will remain sealed in the hole and will not affect groundwater.

• The small amount of oil will seep through the layers of soil contaminating the groundwater.

• The small amount of oil will stop when it reaches a harder layer of soil thus not contaminating the groundwater.

Students designed an experiment to determine how the fertilizer runoff from fields affects ponds. Students used two large outdoor tanks and planted the same variety and amount of aquatic plants in soil placed at the bottom. Students added local fish and samples of local pond water with microorganisms in each tank. One tank was left alone while the other tank had fertilizer added daily. The following table contains possible data sets for algae growth covering the surface of the tanks. Which data set most likely represents the results of the experiment after seven days?

• Data Set A

• Data Set B

• Data Set C

• Data Set D

Which of the following best models the effects of positive human activity on surface and groundwater?

• F

• H

• G

• J

A coastal area that once supported a thriving fishing industry is overfished. The number of species found living in the marine ecosystem decreases. Which of these activities is most likely to increase the natural biodiversity in the area?

• A Building artificial reefs and limiting fishing activity

• B Introducing non-native species to fill unoccupied habitats and banning fishing

• C Building artificial reefs and increasing fishing activity

• D Eliminating non-native species and encouraging fishing for large predatory fish

Which of these human activities is most likely to cause the excessive growth of phytoplankton in the world’s oceans?

• F The use of chemical fertilizers that are carried by runoff into rivers

• G The logging of old-growth forests, which results in erosion

• H The spraying of chemical herbicides that reduce carbon dioxide in the air

• J The mining of fossil fuels, which requires digging underground tunnels

Overfishing reduces the number of fish at a rate that causes long-term reductions in fish populations. The table shows the percentage of fish species in the ocean that were overfished in three different years. Which action would MOST LIKELY reverse the trend shown in the table?

• Increasing the total weight of fish that each ship can remove from the ocean each day

• Requiring ships to return non-adult fish to the ocean so that they can grow and reproduce

• Decreasing the number of policing ships in order to lessen capacity restrictions and regulations

• Promoting meals centered around specific fish species in restaurants in order to increase profits

Ocean water absorbs carbon dioxide from the atmosphere. Carbon dioxide lowers the pH of the ocean water, which is harmful to organisms living in the ocean. Which activity is most likely to decrease the amount of carbon dioxide being added to the ocean water?

• Cutting down rain forests to use the land to farm crops

• Constructing homes on farmland rather than on vacant lots in cities

• Going to school in cars instead of riding the bus with other students

• Using electrically powered devices instead of those powered by fossil fuels