Populations and Resources Amplify

Scientists have been studying the size of three populations in a region. In this ecosystem, lions eat wild pigs, and wild pigs eat frogs. The data showed that all three populations were stable. Then the frog population decreased suddenly. What will likely happen to the size of the wild pig population as a result? The size of the wild pig population will . . .

• increase because the wild pigs and lions will find energy storage molecules elsewhere.

• decrease because there are less energy storage molecules available.

• stay the same because the lions are still stable.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-4

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-LS2-3

NGSS.MS-LS2-4

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 . . .

• increase

• decrease

• stay the same

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 . . .

• 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-LS2-4

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.

A population of rabbits in a forest has been increasing over the past decade. What is the most likely reason for this increase?

• A) More rabbits are being born than are dying.

• B) The forest area has decreased, concentrating the population.

• C) Predators of rabbits have increased in the area.

• D) The rabbit population is migrating to other areas.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

In a controlled experiment, a scientist observes that a population of bacteria doubles every 24 hours. If the initial population is 100 bacteria, what will the population be after 3 days?

• A) 200 bacteria

• B) 400 bacteria

• C) 800 bacteria

• D) 1600 bacteria

A fish population in a lake is stable. What can be inferred about the birth and death rates of the fish?

• A) Birth rate is higher than death rate.

• B) Death rate is higher than birth rate.

• C) Birth rate equals death rate.

• D) Neither birth nor death occurs.