Which of the groups of organisms in the food web would most likely have accumulated the largest concentration of a long-lasting chemical pollutant in their bodies?

Battery-powered cars produce less air pollution than gasoline-powered cars. However, one environmental concern of using battery-powered cars is that batteries –

Insecticides help humans compete with insects for a resource. Which resource is most likely to be preserved for humans through the use of insecticides?

Electric power plants that burn fossil fuels generate billions of tons of carbon dioxide and other gases. How might replacing these power plants with solar cells affect the environment?

Heavy metals such as mercury, cadmium, and nickel are often found in landfills and occasionally leach into rivers, lakes, and other bodies of water. Such heavy metals are toxic to wildlife and to humans. Which of the following sources of environmental contamination is most often associated with these heavy metals?

Which of these is an advantage of producing electricity using solar power plants rather than using coal-fired power plants?

A company has decided to market itself as environmentally friendly. If the company is going to sell calculators, the use of which energy source would produce the fewest by-products and the least waste?

All of these materials can be recycled except –

An increase in greenhouse gases is considered harmful because it —

Sandra puts some pill bugs into an open box. She covers half the box with a piece of cardboard. She then places the box outside on a summer day, and all the pill bugs move under the cardboard.

The pill bugs are most likely responding to which of the following?

All the ponds in an area dried up during a drought. The population of which of the following animals that live in the area is most affected by the drought?

Corals are small marine organisms that live in groups and make hard outer skeletons to protect their bodies. Over time, these outer skeletons can build up to make large coral reefs. Which of the following statements best describes one way the formation of a coral reef changes the ocean ecosystem?

Two geese mate and raise their goslings (baby geese) each year. The table below shows the number of goslings that survive each year over a five-year period.

Which of the following statements best explains why a different number of goslings survives each year?

A hurricane sweeps across a small Caribbean island, killing 50 percent of the herbivore species on the island. Which of the following is the most immediate result?

Populations of Caribbean coral have decreased significantly over the past 30 years due to disease. Which of the following is most likely a major factor leading to the increased amount of disease in the coral?

The northern spotted owl is listed under the Endangered Species Act as a threatened species in its primary range of Washington, Oregon, and California. Which of the following most likely contributed to the northern spotted owl’s population decline?

The snowshoe hare was once common in Maryland. In 1986, researchers in the state noted that the snowshoe hare was no longer found in Maryland. Which statement best explains why the snowshoe hare is no longer found in Maryland?

Nitrogen, a nutrient found in fertilizer, helps plants increase in size. Rainwater runoff often carries fertilizer into ponds and lakes. What effect does excess nitrogen have on organisms in a pond or lake ecosystem?

The water quality of the Chesapeake Bay is measured by the Chesapeake Bay Water Quality Monitoring Program. Scientists measure the salinity, temperature, pH, and oxygen levels to help determine the health of the Bay. Healthy water also contains appropriate amounts of nutrients. Monitoring water quality helps communities make decisions about the Bay.

Which of these would likely be the most immediate result if oxygen levels in the Bay decreased by 90%?

How would building a shopping mall in a wetland area impact the environment?

A population of salamanders that live in a river require clear, fresh water to survive. A flood causes tons of sediment to be suspended in the river. Which of these most likely will happen to the salamander population?

Polar bears swim across large expanses of ocean while hunting for seals, their main source of food. The bears use sea ice as resting spots during their long swims. However, the sea ice is rapidly melting as a result of global warming. Which statememt describes what most likely will happen if global warming continues at its present rate?

The Great Barrier Reef has a number of endangered species that live only in that ecosystem. What would most likely happen if pollution killed most of the coral that made up the reef?

If one species of an organism in an ecosystem suddenly disappeared, which would be the most likely result?

Highways allow people to travel between towns and cities. These highways also divide ecosystems into smaller pieces. Animals can become separated from lakes they use for breeding. For example, tiger salamanders travel long distances to breed at lakes.

How could highway systems affect animals such as the tiger salamander?

A small lake has an algae bloom, and the water is very green. Which change is most likely the cause of the algae growth?

Scientists have been concerned about the reduction of shark populations due to overfishing off the east coast of the United States. Sharks feed on rays, which feed on scallops. Scallops feed on microscopic algae, which they filter from seawater. Without sharks, the rays consume and eliminate scallop beds, harming the scallop fishing industry. This situation demonstrates that