Human Activity and Ecosystems

Reduce, reuse, and recycle are the three R’s of

• Population control

• Pollution

• Natural selection

• Conservation

Fill in the table showing the positive impacts of human interaction on the environment.

• Larger landfills and coal power

• Recycling and solar power

• Recycling and coal power

• Larger landfills and bottling water

What happens when humans cut down forests to build shopping malls?

• Plants and animals thrive in the new environment and pollution decreases.
• New animals species form and plants produce more oxygen.
• The shopping mall reduces the amount of pollution in the area.
• Habitat is altered, plants and animals destroyed, and pollution increases.

____________ is the addition of harmful materials to the environment.

• pollution
• ecotourism
• conservation
• recycle

Pollution can cause harm to the ___________.  

• air
• land
• water
• all of the above

To __________ means to collect old, used materials, and to process them and make them into new items.  

• compost
• decomposer
• litter
• recycle

The acidity of a local stream would most likely be affected by

• a change in the percentage of decomposers living in the stream

• a new source of air pollution

• a new predator species being introduced to the ecosystem

• a decrease in the amount of sunlight that reaches the stream

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

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.

What are some consequences of deforestation?

• increased population in cities
• building of more infrastructure
• soil erosion, loss of biodiversity, loss of ability to remove CO2
• more mercury and cyanide released into rivers