Assessment Items

Instructions: Read the information below and look at the illustration of the food web, then answer the questions.

The organisms in the food web live near large cattle ranches. Over many years, mountain lions occasionally killed a few cattle. One year, a few ranchers hunted and killed many mountain lions to prevent future loss of their cattle.

The arrows point from the organisms being eaten to the organisms that eat them.

1. Which parts of the food web are living?

A. Snake

B. Frog

C. Hawk

D. Grasses

E. All of the above are living

2. Identify two specific populations that most likely increased in number after the cattle ranchers reduced the mountain lion population.

A. Hawk, frog

B. Deer, rabbit

C. Frog, rabbit

D. Deer only

3. The frog and the cricket have a relationship which is best described as...

A. One benefits while the other is harmed.

B. They both benefit from each other.

C. They compete for resources.

D. One benefits while the other is unaffected.

4. If a disease killed all of the grasses, which other populations of organisms in the food web would be affected?

A. Snake

B. Deer

C. Mountain lion

D. Mouse

E. All of the above would be affected

The graph below shows the population sizes of three different organisms in the food web. In year 1, ranchers began to kill the mountain lions near their ranch.

5. Based on the information in the food web, which of the following is the “Unknown Organism” shown in the graph?

A. Rabbits

B. Grasses

C. Hawks

D. Snakes

6. If no mountain lions enter in the ecosystem, what do you expect will happen to the deer?

A. The population of deer will immediately return to their original levels.

B. The population of deer will eventually return to their original levels.

C. The populations of deer will increase and decrease from year to year.

D. The populations of deer will decrease a lot or disappear.

7. In year 5, a new pair of mountain lions migrates to the area around the ranch. How will the deer population change?

A. The deer population will remain at the same level.

B.. The deer population will increase.

C. The deer population will decrease.

D. The deer population will migrate out of the area.

Cathy and Patrice are both ranchers who own many cattle. Their ranches are next to each other.

8. Scientists collect more data about the ranches. Patrice wants to use this new data to strengthen her argument. Which of these new facts will help Patrice make a convincing argument?

A. Rabbits live underground to protect them from cold weather.

B. Rabbits eat more grasses and grains than the other herbivores

9. Fill in the blanks to explain why your choice strengthens Patrice’s argument.

Fewer mountain lions would lead to a(n) _________________ (increase or decrease) in rabbits. This would _________________ (reduce or increase) the amount of grains for the ranchers’ cattle.

10. Show how Patrice could support her claim that mountain lions are good for the ranches. Use the food web.

Mountain lions are good for the ranches because rabbits are competitors with cattle. Because

a. mountain lions

b. hawks

are predators of rabbits, more of them would mean fewer rabbits. This would cause there to be

a. more

b. less

grain for our cattle, which is good for our ranches.

Another rancher named Angel begins talking with Cathy and Patrice. Angel heard both of their arguments, but she has a different claim.

11. Angel has several pieces of evidence that are all true. What evidence best supports Angel’s claim?

A. Mountain lions can eat hundreds of mice every year.

B. Deer do not eat the same kinds of grasses and grains as the cattle.

C. 0.5% of all cattle deaths are due to mountain lions.

D. Rabbits eat the same grain as cattle.

12. Why does the evidence you picked support Angel’s claim?

A. Without top predators, ecosystems become imbalanced.

B. Too many rabbits will eat grasses and grains that the cattle need to survive.

C. Mice and rabbits are much less important to the ecosystem than mountain lions.

D. Mountain lions kill so few cattle that it has a very small effect on the ranch.

13. Why is Angel’s argument more convincing than Cathy’s argument?

Angel said: Mountain lions are not an important factor for the ranches

Cathy said: Mountain lions are bad for the ranches

Angel’s argument…

A. uses the food web to identify predator/prey relationships.

B. uses new data that explain why Cathy’s argument is not relevant.

C. supports Patrice’s argument that mountain lions are good for the ranches.

D. is carefully constructed which makes it very convincing.