Ecosystems

Where does the alligator get its food molecules?

• from the grocery store

• through many other organisms that eat one another

• through the sun's energy

• from the Plover bird

Tags

NGSS.MS-LS2-3

Elephants eat grass. What is the consumer population?

• Elephants

• Grass

• Both are the consumer population

• Neither are the consumer population

Tags

NGSS.MS-LS2-1

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-LS2-4

A population of bluefish lives in the Gulf of Mexico. Over the last 50 years, the size of the bluefish population has decreased. What best explains the decrease in the size of the bluefish population?

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

• More bluefish were born than died.

• Fewer bluefish were born than died.

• The bluefish population is always decreasing because bluefish are always being eaten.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

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

• stay the same. Opossums and foxes do not eat each other, so the number of births and deaths in the fox population will stay the same.

• decrease. The larger opossum population will leave fewer energy storage molecules for all other populations in the ecosystem, so the fox population will reproduce less. This will lead to fewer births than deaths in the fox population.

• decrease. Fewer energy storage molecules will be available to the fox population from the smaller rat population, so the fox population will reproduce less. This will lead to fewer births than deaths in the fox population.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

NGSS.MS-LS2-3

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?

• decrease. The larger crab population will leave fewer energy storage molecules available in the ecosystem for the shark population, so there would be fewer births in the shark population.

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

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

• stay the same. Sharks do not eat crabs, so the number of births and deaths in the shark population will stay the same.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

NGSS.MS-LS2-2

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.

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

• More mice were born than died.

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

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. 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-LS2-4

NGSS.MS-LS2-3

NGSS.MS-LS2-2

Moon Jelly populations are decreasing. Why?

• There are more births than deaths

• There are less births than deaths

• The population is stable

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

What do organisms use energy for?

• Digesting food

• Reproduction

• Moving around

• Everything they do to survive

Tags

NGSS.MS-LS1-7

NGSS.MS-LS2-3

NGSS.MS-LS1-6