Amplify Populations and Resources

Scientists have been studying the size of three populations in a swampland. In this ecosystem, herons (a type of bird) eat frogs, and frogs eat dragonflies. The data showed that all three populations were stable. Then the dragonfly population increased suddenly. What will likely happen to the frog population as a result?

The size of the frog population will . . .

• decrease. The larger dragonfly population will take more energy storage molecules from the ecosystem, leaving fewer available for the frog population. This will lead to fewer births in the frog population.

• increase. The larger dragonfly population will provide more energy storage molecules for the frog population, so they will reproduce more. This will lead to more births than deaths in the frog population.

Tags

NGSS.MS-LS2-1

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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?

• increase. The smaller eagle population will leave more energy storage molecules for all other populations in the ecosystem, so all populations will reproduce more. This will lead to more births in the bear population.

• increase. More energy storage molecules will be available to the bear population from the larger trout population, so the bear population will reproduce more. This will lead to more births than deaths in the bear population.

Tags

NGSS.MS-LS2-1

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?

• 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.

• 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

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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?

• increase because there are less lizards eating them.

• decrease because there are more lizards eating them.

• stay the same

• increase because there will be more energy storage molecules available for the fireflies to eat.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

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In Australia, both opossums and foxes eat rats. The sizes of the populations have been stable for the last 12 years, but recently the size of the opossum population increased. What will likely happen to the fox population?

• increase because there will be more rats to make energy.

• decrease because the opossum population is taking more energy storage molecules from the rats.

• stay the same because there are still energy storage molecules available.

• decrease because the opossum population is using the fox population for energy storage molecules.

Tags

NGSS.MS-LS2-1

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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?

• 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

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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

Scientists have been studying the size of three populations in a swampland. In this ecosystem, herons (a type of bird) eat frogs, and frogs eat dragonflies. The data showed that all three populations were stable. Then the dragonfly population increased suddenly. What will likely happen to the frog population as a result? The size of the frog population will . . .

• increase

• decrease

• stay the same

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-4

In an ecosystem, if the population of a primary consumer increases significantly, what is the most likely immediate effect on the population of the producers?

• A) The producer population will increase due to more energy being available.

• B) The producer population will decrease due to increased consumption.

• C) The producer population will remain stable as they are not affected by consumers.

• D) The producer population will fluctuate unpredictably.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-3

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Which of the following best describes the concept of carrying capacity in an ecosystem?

• A) The maximum number of individuals of a species that an ecosystem can support indefinitely.

• B) The minimum number of individuals needed for a species to survive.

• C) The average number of individuals in a population over a year.

• D) The total biomass of all species in an ecosystem.