Ecology human impact

Which animal has modified ecosystems more than any other animal and has had the greatest negative impact on world ecosystems?

• Gypsy moth
• zebra mussel
• human
• shark

Continued depletion of the ozone layer will most likely result in

• an increase in skin cancer among humans
• a decrease in atmospheric pollutants
• an increase in marine ecosystem stability
• a decrease in climatic changes

Which human activity would most likely deplete finite resources?

• use of natural enemies to eliminate insect pests
• development of wildlife refuges
• governmental restriction of industrial pollution
• uncontrolled population growth

One irreversible effect of both deforestation and water pollution on the environment is the

• extinction of species
• thinning of the ozone shield
• depletion of atmospheric carbon dioxide levels
• increase in renewable resources 

Which situation has had the most negative effect on the ecosystems of Earth?

• use of air pollution controls 
• use of natural predators to control insect pests 
• recycling glass, plastic, and metals 
• increasing human population

Water from nearby rivers or lakes is usually used to cool down the reactors in nuclear power plants. The release of this heated water back into the river or lake would most likely result in

• an increase in the sewage content in the water
• a change in the biodiversity in the water 
• a change in the number of mutations in plants growing near the water 
• a decrease in the amount of sunlight necessary for photosynthesis in the water

African elephant tusks consist of high-quality ivory. In recent years, the elephant population in certain African wildlife preserves has decreased. This decrease is most likely due to

• air pollution 
• human exploitation 
• biocide use
• importation of Japanese beetles

 One reason why people should be aware of the impact of their actions on the environment is that

• ecosystems are never able to recover once they have been adversely affected
• . the depletion of finite resources cannot be reversed
• there is a decreased need for new technology
• there is a decreased need for substances produced by natural processes

Continued depletion of the ozone layer will most likely result in

•  an increase in skin cancer among humans
•  a decrease in atmospheric pollutants
• an increase in marine ecosystem stability
• a decrease in climatic changes

Which human activity is correctly paired with its likely future consequence?

• overfishing in the Atlantic — increase in supply of flounder and salmon as food for people
• development of electric cars or hybrid vehicles — increased rate of global warming
•  use of fossil fuels — depletion of underground coal, oil, and natural gas supplies
• genetically engineering animals — less food available to feed the world’s population