Unit 1 Lesson 8 Science

1. Clearing prairies to plant crops is a negative change to ecosystems because

• people plant trees to replace the ones they cut down.

• the way organisms interact in food webs is disrupted.

• humans are using the land to build farms instead of homes.

• organisms interact in the same ways before and after the change.

2. Anything that people add to the environment that harms living things is considered

• pollution.

• chemical waste.

• damage.

• human development.

3. All the goods and services people need or want are either made of __________ or produced using them.

4. After an ecosystem has been destroyed, it

• sometimes can be restored.

• always slowly recovers on its own.

• can never recover from the damage.

• usually returns back to how it was before.

5. A(n) ________ species is a non-native organism that causes harm to the environment.

6.The Burmese python is a snake native to South Asia. Young snakes were brought into the United States and sold as pets. When the snakes grew too large to care for, some owners released them into the natural environment. In Florida, where the climate is warm and wet, Burmese pythons can survive and reproduce. Which fact about Burmese pythons makes them an invasive species?

• They swim and climb trees.

• They have natural enemies in Florida.

• They cause harm to their new ecosystem.

• They are the largest snake species in Florida.

7.Does a factory such as this oil refinery have a positive or negative effect on ecosystems, and why?

• A positive effect, because factories provide energy for plants and animals

• A positive effect, because waste from factories does not disrupt ecosystems

• A negative effect, because factories produce pollution which harm living things

• A negative effect, because burning fuels releases helpful chemicals into the air