Which of the following would have a negative impact on an ecosystem

• deforestation

• planting trees

• recycling paper

6. A squirrel makes a change to its environment when it —

• climbs a tree
• digs a hole to bury an acorn
• collects acorns
• jumps from tree to tree

What do scientist call organisms that are not native to an ecosystem and cause harm to native organisms?

• native plants

• invaders

• invasive species

• natural species

When a certain population becomes too large, and it harms or changes the quality of life in that environment, we have an...

• a population

• overpopulation

• pollution

An ______________ is a system made up of all the biotic and abiotic factors in an area and all the interactions among them.

• ecosystem
• habitat
• population
• biodiversity

Huge areas of the Amazon Rainforest are being cut down. What effect could this have on the carbon-dioxide/oxygen cycle if the removal of so many plants and trees continues?

• Carbon dioxide levels increase

• Oxygen levels increase

• Carbon dioxide levels decrease

• Nitrogen levels decrease

There are many large-mouth bass, a type of fish, living in a small lake near Waco, Texas. How would increased fishing in the lake effect the lake ecosystem?

• Predators of the bass might starve due to loss of a food source

• The population of the bass’ prey would decrease.

• The bass would spend more time swimming near the surface

• Water level in the lake would decrease as more fishing took place

What does it mean when an organism is endangered?

• They completely die out

• They are in danger of completely dying out

• They are extinct

• They are doing just fine

What does deforestation mean

• When humans add poisons to the environment

• When animals add poisons to the environment

• When humans cut down forest trees

• When forests grow high and beautiful

How does overgrazing by herbivores change an environment?

• It causes a lot of erosion and vegetation(producers) can't grow.

• It makes the land beautiful and lush

• There is no problem when grazers eat too much grass

• The grazers add nutrients to the land