Population Resources

Scientists have been studying the size of three populations in a grassland. In this ecosystem, snakes eat rats, and rats eat grasshoppers. The data showed that all three populations were stable. Then the grasshopper population decreased suddenly. What will likely happen to the size of the rat population as a result?

• stay the same. The size of their consumer population did not change, so the number of deaths in the rat population did not change. There will be the same number of births and deaths in the rat population.

• increase. The smaller grasshopper population will need fewer energy storage molecules so there will be more energy storage molecules available for the rat population to reproduce. This will lead to more births in the rat population.

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

• decrease. The smaller grasshopper population provides fewer energy storage molecules for the rat population, so the rat population will reproduce less. This will lead to fewer births than deaths in the rat population.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-4

If the resource population decreases, then the consumer population will....

• Increase

• Stay the same

• Decrease

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-4

Which vocabulary word is defined as: when two or more populations use the same resource, such as the same food source

• change

• competition

• ecosystem

• glucose

Which word correctly fills both blanks: A ________ in the size of a resource population can cause the number of births in its consumer population to _________.

• sample

• energy

• change

• competition

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Under which condition will the population size be stable?

• When there are more births than deaths.

• When there are more deaths than births.

• When the number of births and deaths in a given time are equal.

• The population size is always stable.

What causes a population size to increase?

• The number of births is greater than the number of deaths.

• The number of deaths is greater than the number of births.

• The number of births and the number of deaths is equal.

Tags

NGSS.HS-LS4-2

A larger resource population provides more energy storage molecules to its consumer population, causing ______ to increase.

• deaths

• births

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-3

How would an increase to the opossum population affect the fox population?

• The fox population would increase.

• The fox population would decrease.

• The fox population would stay the same.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

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 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

NGSS.MS-LS2-2

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 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

NGSS.MS-LS2-4