Populations and Ecosystems

All of the organisms of the same species living in the same area is a:

• Community

• Ecosystem

• Population

• Biosphere

Five green and speckled frogs sitting on a log, eating delicious bugs.

Which level of organisation is this?

• Community

• Ecosystem

• Population

• Biosphere

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

• All the mice die and no mice were born

• More mice were born than died

• Lots of mice immigrated into the population

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

When an environment has reached its carrying capacity for a certain population, which of the following is true?

• Birth rate and immigration rate are equal death rate and emigration rate

• Birth rate and immigration rate are greater than death rate and emigration rate

• Birth rate and immigration rate are less than death rate and emigration rate

• Birth rate is exponential

What is the approximate carrying capacity for the deer population in the graph?

• 100

• 80

• 60

• 20

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Which of the following describes how an abiotic factor can impact the population in an ecosystem?

• A parasite that invades a host can reproduce and cause a decline in the host species population.

• Organisms that compete for the same resources will keep each other from overpopulating.

• Predators will prevent herbivores from depleting the plants and other resources in an ecosystem.

• Seasonal variations in temperature can cause some of the individuals in a population to die.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Which pair of factors is most likely to increase the size of the population?

• births and deaths

• births and immigration

• deaths and emigration

• immigration and emigration

A population of kangaroos grows briefly and then stabilizes. What does the leveling off indicate?

• The population has reached the carrying capacity of the environment.

• The population has exceeded the carrying capacity of the environment.

• The population is affected by a density-independent limiting factor.

• The population is no longer able to adapt to environmental changes.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Which of the following is a density-dependent limitation of population growth?

• A forest fire

• Competition with other organisms for resources

• Pollution in the water

• Drought (greatly reduced rainfall)

Tags

NGSS.MS-LS2-4

A disease kills most of the predator population. Which of these is the most likely effect on the prey population?

• The prey will also be killed by the disease.

• The prey population will decrease in size because there are fewer predators.

• The prey population will increase in size because there are fewer predators.

• There will be no effect on the prey population.

Tags

NGSS.HS-LS2-6

NGSS.HS-LS4-5