Changes in Ecosystems

When an ecosystem is balanced, it is called:

• a climax community

• ecological succession

• dynamic equilibrium

• eutrophication

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NGSS.MS-LS2-3

What factor most likely led to the decrease in the bird populations shown on the graph?

• Introduction of a new species

• Loss of food source

• Loss of habitat

• Use of pesticides

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NGSS.MS-LS2-1

NGSS.MS-LS2-4

From 1965 to 1970, which pattern did scientists observe?

• A drop in wolf population and a drop in moose population

• An increase in wolf population and a drop in moose population

• A drop in wolf population and in an increase in moose population

• An increase in wolf population and an increase in moose population

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NGSS.MS-LS2-1

NGSS.MS-LS2-4

Why does this occur?

• A decrease in the amount of sunlight creates a better environments for plants

• The new sediment causes the original plants in the area to evolve into new species

• The new sediment causes the original plants in the area to become extinct

• The new sediment provides a place for more plants to grow

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NGSS.MS-LS1-5

NGSS.MS-LS2-4

Which environment factor may have contributed to the increase in the rabbit population?

• Decrease in resources

• Decrease in predators

• Increase in disease

• Increase in pollution

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NGSS.MS-LS2-1

NGSS.MS-LS2-4

Farms are typically located along rivers and streams in Virginia. Farmers often use pesticides to keep insects from eating their crops. What impact might this practice have on the aquatic insect population near the farms?

• it may increase the population of aquatic insects

• it may decrease the population of aquatic insects

• it may cause genetic mutations in the population of aquatic insects

• it may diversify the population of aquatic insects

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NGSS.MS-LS1-5

NGSS.MS-LS2-4

Which statement best describes these two species?

• Species A is a producer and species B is its consumer

• Species A is a host and species B is its parasite

• Species A is a predator and species B is its prey

• Species A is a scavenger and species B is its decomposer

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NGSS.MS-LS2-2

Which of the following statements about the bluegill population is supported by the data shown in this graph?

• An algae bloom reduced dissolved oxygen from 1992 to 1993

• The amount of food increases from 1994 to 1995

• There was a decrease in predators from 1995 to 1996

• Fisherman caught fewer bluegill from 1996 to 1997

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NGSS.MS-LS2-1

NGSS.MS-LS2-4

Which of the following BEST describes the change in the size of populations in an ecosystem over time?

• Population numbers are stable over centuries

• Population numbers change each month

• Population numbers change noticeably on a day-to-day basis

• Population numbers normally change with the seasons

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NGSS.MS-LS2-1

NGSS.MS-LS2-4

Which of the following conditions may result in an increase in a specific deer population?

• A longer hunting season

• A warm winter with little snow or ice

• Cutting down trees for wood

• Very little rain

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NGSS.MS-LS2-1

NGSS.MS-LS2-4