Ecosystem Test # 3 Review

Wood ducks build their nests in holes in trees near lakes. If some of the trees were removed from around the lake, how would the wood ducks be affected?

• Wood ducks would become a new species
• Wood ducks would lay more eggs in each nest.
• Wood ducks would increase their competition for nests.
• Wood ducks would begin building their nestson the ground

It is common to see wild animals like deer and coyotes in large cities and neighborhoods. Which is most likely a reason the animals are found in these areas?

• They prefer to be near houses.
• They prefer to be near people.
• Their habitat is increasing in size.
• Their habitat is decreasing in size.

Kodiak bears live in a certain part of southwestern Alaska. How would decreasing the size of the habitats for territorial animals like Kodiak bears most likely affect them?

• They would become herbivores.
• They would become endangered.
• They would move to another territory.
• They would have cubs in other locations.

Which is most likely responsible for the pollutants that enter a wetland ecosystem after a heavy rain?

• animal waste
• human chemical use
• atmospheric conditions
• changes in daily temperatures

Which is one way people often destroy animal habitats?

• by building new homes
• by recycling waste products
• by producing new energy sources
• by creating new varieties of plants

For many years, farmers used a chemical called DDT to kill insects in theircrops. Gradually, the chemical made its way into streams, rivers, andlakes. After DDT had been used for several years, bald eagles began laying eggs with very thin shells and became endangered. Which is most likely a reason why this happened to bald eagles?

• The water they drank had minerals in it.
• The fish they ate had pesticides in them.
• There was not enough food for them to eat.
• There was not enough water for them to drink.

A pond has become overgrown with algae. The fish and plants in the pond are beginning to die. Which human activity would most likely be responsible for the decrease in pond life?

• people throwing garbage near a road
• logging companies cutting trees in forests
• farmers using excess fertilizers on crops
• factories producing smoke that pollutes the air

Maria notices oil leaking from a car onto the street outside her house.She lives beside a lake and knows the oil will flow into the lake. What is the best thing for Maria to do at this point?

• Alert local officials immediately;they can take action to protectthe quality of the water.
• Write a letter in the local paper discussing ways to conserve water in homes.
• Go outside and use cleaning products to clean up the oil spill.

Which is most likely an effect of construction on a forest ecosystem?

• Construction will decrease the amount of sunlight for the ecosystem.
• Construction will increase the number of trees and smallerplants growing in the ecosystem.
• Construction will increase the amount of food for organisms inthe ecosystem.
• Construction will decrease theamount of natural cover and nesting places for organisms in the ecosystem.

Some diving sea birds, such as puffins, often eat sand eels as their major source of food. What would most likely happen as a result of over fishing sand eels?

• The size of the sand eels would become larger.
• The sand eels would move to fresh waters.
• The sea birds would eat other sources of food.
• The sea birds would move to other areas to hunt for sand eels.