Ecological Relationships

1. If a disease strikes the snake population in the food chain shown, what will be the initial effect on the populations of hawks and rabbits?

• •  A. The populations of hawks and rabbits will decrease.

• •   B. The populations of hawks and rabbits will increase.

• •  C. The population of hawks will increase. The population of rabbits will decrease.

• • D. The population of hawks will decrease. The population of rabbits will increase.

In the stable food chain shown below, what would you expect to happen initially if you were to suddenly double the population of rabbits?

• • A. The populations of the other three species would also increase.

• •  B. The populations of the other three species would decrease.

• •  C. The grass population would decrease. The snake population and hawk population would increase.

• • D. The grass population and hawk population would decrease. The snake population would increase.

What event within the food chain might lead to the graph shown below?

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  • A. A disease in the population of rabbits.

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• •  B. A disease in the population of snakes.

• • C. A disease in the population of hawks.

• • D. It is impossible to tell which of the above occurred.

What most likely caused the rabbit population to decrease over the first time unit shown in the following graph?

• • A. A disease in the population of rabbits.

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• • B. A decreasing population of grasses.

• • C. An increasing population of hawks.

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  • D. A higher than normal population of snakes.

Trapping has severely reduced the population of rabbits in an ecosystem, as shown in the bar graph below. What is the most likely effect this will have on other organisms?

• •  A. The snake population will decrease rapidly and the grass population will increase rapidly.

• •  B. The hawk population will increase rapidly and the rabbit population will decrease rapidly.

• C. The grass population will decrease rapidly and the snake population will increase rapidly.

• D. The grass, rabbit, snake, and hawk populations will all decrease rapidly.

What happens to the rabbit population on year 4?

• It begins to decrease

• It stays the same

• It increases

• It reaches carrying capacity

In the year 1900, the lynx population was very low. What could have caused this?

• The hare population increased.

• The producers increased

• Their prey population, the hare, decreased because the lynx ate a lot of them just before that year.

• none of the above

Who does the bird compete with for food?

• owl

• fox

• grasses

• carrots

What can you conclude when these 2 populations (aurelia and caudatum) are grown together in the same petri dish?

• caudatum outcompetes aurelia

• aurelia outcompetes caudatum

• neither outcompetes the other

What could have caused the population to decrease after the year 1850?

• The population reached the maximum amount that the limiting factors could support.

• more immigration than usual

• more rainfall

• more producers