LE: Human Impact on Ecosystems Online Review

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.


By causing atmospheric changes through activities such as polluting and careless harvesting, humans have
caused the destruction of habitats
affected global stability in a positive way
established equilibrium in ecosystems
replaced nonrenewable resources


Which human activity would have the most direct impact on the oxygen – carbon dioxide cycle?
reducing the rate of ecological succession
decreasing the use of water
destroying large forest areas
enforcing laws that prevent the use of leaded gasoline


To minimize negative environmental impact, a community should
approve the weekly spraying of pesticides on the plants in a local park
grant a permit to a chemical manufacturing company to build a factory by one of its lakes, with no restrictions on waste disposal
make a decision about building a new road in a hiking area based only on the economic advantages
set policy after considering both the risks and benefits involved in building a toxic waste site within its boundaries


El Niño is a short-term climatic change that causes ocean waters to remain warm when they should normally be cool. The warmer temperatures disrupt food webs and alter weather patterns.Which occurrence would most likely result from these changes?
Some species would become extinct, and other species would evolve to take their place.
Some populations in affected areas would be reduced, while other populations would increase temporarily.
The flow of energy through the ecosystem would remain unchanged.
The genes of individual organisms would mutate to adapt to the new environmental conditions.


Which statement illustrates how human activities can most directly change the dynamic equilibrium of an ecosystem?
A hurricane causes a stream to overflow its banks.
Increased wind increases water evaporation from a plant.
Water pollution causes a decrease in fish populations in a river.
The ozone shield helps prevent harmful radiation from reaching the surface of Earth.


Some factories have a negative impact on Earth's ecosystems because they
have high energy demands that require the use of fossil fuels and nuclear fuels
utilize agricultural technology that decreases soil erosion
decrease the need for finite resources
limit the amount of emissions produced each year


Which factor is not considered by ecologists when they evaluate the impact of human activities on an ecosystem?
amount of energy released from the Sun
quality of the atmosphere
degree of biodiversity
location of power plants


A new type of fuel gives off excessive amounts of smoke. Before this type of fuel is widely used, an ecologist would most likely want to know
what effect the smoke will have on the environment
how much it will cost to produce the fuel
how long it will take to produce the fuel
if the fuel will be widely accepted by consumers

Short Answer


Recycling can extend the use of nonrenewable resources but can not restore them. Humans can restore renewable resources to reduce some negative effects of increased human consumption. Identify one resource that is renewable, and describe one specific way humans can restore this resource if it is being depleted.


   Mountain lions and big horn sheep are part of the natural food web in the Sierra Nevada mountains. The Fish and Wildlife Service recently declared these sheep an endangered species. This action could lead to the shooting of mountain lions.
   a.  State one reason placing these sheep on an endangered species list could lead to the shooting of mountain lions where the sheep live.
   b.  State two reasons some people would oppose the shooting of the mountain lions.


Choose one ecological problem from the list below.
      Ecological Problems
         Global warming
         Destruction of the ozone shield
         Loss of biodiversity
Discuss the ecological problem you chose. In your answer be sure to state:
• the problem you selected and one human action that may have caused the problem
one way in which the problem may negatively affect humans
one positive action that could be taken to reduce the problem


There are a number of possible methods to control an invasion of gypsy moths in a city
park. Several alternatives are listed below.
Write the letter of the method you would use and give an ecologically sound reason for
your choice.


In the early 1980s, scientists discovered holes in the ozone shield surrounding Earth. State one negative effect this environmental change could have on humans.


All living organisms are dependent on a stable environment.
   Describe how humans have made the environment less stable by:
      • changing the chemical composition of air, soil, and water [1]
      • reducing the biodiversity of an area [1]
      • introducing technologies [1]
   Describe two specific ways recently used by humans to reduce the amount of
      chemicals being added to the environment. [2]


   The Pine Barrens is a government-protected environment located on the eastern end of Long Island. A proposal has been made to allow a shopping mall to be built in the middle of the Pine Barrens. Although the developer has promised jobs for people in the surrounding communities, some community members oppose the building of the mall due to the negative effects it would have on this fragile ecosystem.
   Identify two negative effects this mall would most likely have on the Pine Barrens.
Base your answers to the following questions on the information below and on your knowledge of biology.
      The planning board of a community held a public hearing in response to complaints by residents concerning a waste-recycling plant. These residents claim that the waste-hauling trucks were polluting air, land, and water and that the garbage has brought an increase in rats, mice, and pathogenic bacteria to the area. The residents were insistent that the waste-recycling plant be closed permanently.
      Other residents recognized the health risks but felt that the benefits of waste recycling outweighed the health issues.


Identify two specific health problems that could result from living near the waste recyclingplant.


State one cause of a health problem that can be associated with the presence of the waste recyclingplant.


State one ecological benefit of recycling wastes.

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