Invasive Species

Why do invasive animals cause so much harm to local ecosystems?

1. Their prey has no natural defenses against them.

2. They can spread disease.

3. They reduce the food and water supplies available.

• (A) 1 and 2

• (B) 1 and 3

• (C) 2 and 3

• (D) 1, 2 and 3

Which sentence from the article would be MOST important to include in a summary of the article?

• (A) Invasive species can damage native habitats, spread diseases, cause extinctions and require a lot of cleanup

• (B) In some cases, government officials have encouraged the introduction of invasive species.

• (C) Meanwhile, in the Florida Everglades, Burmese pythons are causing trouble.

• (D) Some invasive plants can be turned into paper.

What happens to the local plants if an invasive plant species takes hold in an ecosystem?

• (A) Some local plants may lose the competition for resources and die.

• (B) Some local plants may immediately develop new defenses.

• (C) Some local plants may start to take in different nutrients to store them.

• (D) Some local plants may quickly develop more efficient water use systems.

Which statement is a CENTRAL idea of the article?

• (A) Cane toads are native to South America even thought they are also found in Australia.

• (B) Eating some invasive species is a good way to control them.

• (C) Human activity is the main cause of the spread of invasive species.

• (D) Invasive feral pigs are a problem in Hawaii.

The harm caused by invasive species is not limited by just their immediate impact on food webs.

Which invasive species' case study provides the best evidence of the further-reaching impact?

• (A) feral pigs

• (B) cane toads

• (C) brown tree snake

• (D) Burmese python

Read the following selection.

In the 1930s, the government encouraged people in the southern United States to plant the fast-growing vine. They hoped this would prevent soil erosion. But the kudzu quickly grew out of control, earning it the name "the vine that ate the South."

Why did the author include this event?

• (A) to show that invasive species are spread through human activity, even if the intentions for spreading them are good

• (B) to show that the government made a poor decision when it introduced the kudzu plant in the South

• (C) to highlight the importance of learning as much as possible about an invasive species before introducing it

• (D) to highlight how soil erosion is a major environmental problem in the South

Which invasive species' case study provides evidence that ecosystems could still be altered even if the invasive species was successfully removed?

• (A) The cane toad is toxic to predators.

• (B) The lionfish caused economic damage.

• (C) The Burmese python bred with local snakes.

• (D) Potatoes and tomatoes were introduced as food.

What does the author do to build understanding of invasive species?

• (A) The author explains why countries need to have strict laws about what organisms can enter and exit their borders.

• (B) The author explains the science behind why some species cause harm to the local environment while others do not.

• (C) The author offers several detailed examples of invasive species and their effects on the environment.

• (D) The author offers several detailed examples of how to stop the spread of invasive species.