Populations and Resources Unit Test

In the Arctic region, polar bears eat seals, and seals eat cod (a type of fish). In the last 7 years, the sizes of all the populations stayed stable, but recently the size of the polar bear population decreased. What will likely happen to the cod population?

The size of the cod population will . . .

• increase because when one population increases, the others do too.

• decrease because less seals are being eating, making them increase, and eating more cod.

• stay the same

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-3

NGSS.MS-LS2-4

A population of tigers lives in Bangladesh. Over 50 years, the size of the tiger population increased. What best explains the increase in the size of the tiger population?

• A lot of tigers were born and none of them died.

• Fewer tigers were born than died.

• The tiger population is always increasing because no animal eats tigers.

• More tigers were born than died.

In the Arctic Ocean, sharks eat whales, and whales eat crabs. In the last 10 years, the sizes of the populations have been stable, but recently the size of the crab population increased. What will likely happen to the shark population?

The size of the shark population will . . .

• increase

• decrease

• stay the same

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-4

A large population of ducks lives in an area with a lake. In the last 40 years, the size of the duck population has stayed the same. What must be true about the duck population during the last 40 years?

• The number of ducks that were born was the same as the number of ducks that died.

• Humans started protecting the duck population so they stopped dying.

• No ducks were born and no ducks died.

• The ducks did not have any baby ducks during these years.

In North America, both bears and eagles eat trout. The sizes of the populations have been stable for the last 9 years, but recently the size of the eagle population decreased. What will likely happen to the bear population?

The size of the bear population will . . .

• increase

• decrease

• stay the same

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-4

A population of mice lives in the northeastern United States. Over the last 50 years, the size of the mouse population decreased. What best explains the decrease in the size of the mouse population?

• Fewer mice were born than died.

• More mice were born than died.

• A lot of mice died and no new mice were born.

• The mouse population is always decreasing because mice are always being eaten.

Tags

NGSS.MS-LS2-4

Scientists have been studying the size of three populations in Peru. In this ecosystem, pumas (large wild cats) eat deer, and deer eat grass. The data showed that all three populations were stable. Then the puma population increased suddenly. What will most likely happen to the size of the deer population as a result?  The size of the deer population will . . .

• stay the same. The size of their resource population did not change, so the amount of energy storage molecules available for the deer did not change. There will be the same number of births and deaths in the deer population.

• increase. An increase in the size of one population leads to an increase in the sizes of all other populations in the ecosystem.

• decrease. The larger puma population will leave fewer energy storage molecules available in the ecosystem for the deer. The deer population will reproduce less, leading to fewer births in the deer population.

• decrease. The larger puma population will need more energy storage molecules, so they will eat more deer. This will lead to more deaths than births in the deer population.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-4

In the Arctic region, polar bears eat seals, and seals eat cod (a type of fish). In the last 7 years, the sizes of all the populations stayed stable, but recently the size of the polar bear population decreased. What will likely happen to the cod population? The size of the cod population will . . .

• decrease. A decrease in the size of one population leads to a decrease in the sizes of all other populations in an ecosystem.

• decrease. The smaller polar bear population will lead to more seals. The larger seal population will need more energy storage molecules to reproduce, so they will eat more cod. This will lead to more deaths than births in the cod population.

• stay the same. Polar bears do not eat cod, so the number of births and deaths in the cod population will stay the same.

• increase. The smaller polar bear population will leave more energy storage molecules available in the ecosystem for the cod population, so there will be more births in the cod population.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-3

NGSS.MS-LS2-4

A population of tigers lives in Bangladesh. Over 50 years, the size of the tiger population increased. What best explains the increase in the size of the tiger population?

• A lot of tigers were born and none of them died.

• The tiger population is always increasing because no animal eats tigers.

• Fewer tigers were born than died.

• More tigers were born than died.

Tags

NGSS.MS-LS1-4

NGSS.MS-LS1-5

NGSS.MS-LS2-4

Scientists have been studying the size of three populations in a grassland. In this ecosystem, lizards eat fireflies, and fireflies eat gnats (a type of insect). The data showed that all three populations were stable. Then the lizard population decreased suddenly. What will most likely happen to the size of the firefly population as a result? The firefly population will . . .

• increase. The smaller lizard population will need fewer energy storage molecules so they will eat fewer fireflies. This will lead to fewer deaths than births in the firefly population.

• increase. The smaller lizard population will leave more energy storage molecules available for the firefly population to reproduce more. This will lead to more births in the firefly population.

• stay the same. The size of its resource population did not change, so the amount of energy storage molecules available for the fireflies did not change. There will be the same number of births and deaths in the firefly population.

• decrease. A decrease in any population causes a decrease in the sizes of all other populations in the ecosystem.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-4