Human Impact Lvl.2

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

Approximately 75 percent of the Earth's surface is covered in water. So why is water considered such a precious resource?

• The greenhouse effect is causing most of the world's freshwater to be trapped in the atmosphere
• Only a small fraction of the Earth's water is freshwater available for drinking and irrigation
• Each year, more freshwater is being trapped in icecaps located at the North and South Poles
• Global warming caused by greenhouse gas emissions will likely cause Earth's oceans to evaporate

Many common products, such as wooden furniture, paper, and books, are made from trees. Which of the following is a likely consequence of humans cutting down a forest in order to make use of the natural resources there? 

• the decrease of chemical runoff into the oceans
• increased acid rain
• the increase of light pollution in cities
• the destruction of habitats

Wastes produced by agriculture, households, industry, mining, and other human activities can end up in ______________.

• groundwater
• streams and rivers
• oceans
• All of these choices

When fertilizers run off farmland into streams and ponds, the nitrogen content of the water increases. This can lead to rapid growth of algae in a process called eutrophication. How can this process affect other organisms in the water?

• Oxygen is used up as algae is decomposed, reducing the amount available to other organisms.
• The water becomes better able to support aerobic organisms.
• The algae provide food for fishes and other organisms, leading to decreased algae populations.
• The extra nitrogen provides additional food for the other organisms, increasing their population.

Wind is a __________ energy resource.

• Renewable
• Nonrenewable

The fish-eating bird in this food chain likely have the LARGEST _________.

• concentration of DDT
• amount of energy
• biomass
• numbers

What is biomagnification?

• the increase in biomass at higher trophic levels in an ecosystem
• the increase in concentration of a nonbiodegradable compound at higher trophic levels in an ecosystem
• The chemicals go away as the predator eats its prey
• A pollutant moves up  the food chain and grows larger as the predator eats its prey 

Which member of the food chain is MOST affected by mercury, a fresh water pollutant?algae --> zooplankton--> small fish --> large fish --> hawk

• algae
• zooplankton
• large fish
• hawk

Using pesticides like DDT may cause

• healthier teeth
• Eutrophication in lakes
• no effect
• Biomagnification in a food chain