Population & Resources review 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

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. The smaller lizard population will need fewer energy storage molecules so they will eat fewer fireflies. This will lead to fewer deaths than births in the firefly population.

• increase. The smaller lizard population will leave more energy storage molecules available for the firefly population to reproduce more. This will lead to more births in the firefly population.

• stay the same. The size of its resource population did not change, so the amount of energy storage molecules available for the fireflies did not change. There will be the same number of births and deaths in the firefly population.

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

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. 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-LS2-3

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

What do birds such as eagles and hawks need energy for?

• flying

• breathing

• digesting food

• all of the above

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NGSS.MS-LS1-7

Two organisms fighting for the same resources is known as:

• predation

• competition

• symbiosis

• dancing

When a populations is known to be STABLE, it:

• there are more deaths

• there are more births

• stays mostly the same, over time

• horses live there

Energy storage molecules are:

• molecules required only for the birth rate

• potatoes

• a molecule organisms use to stabilize a population

• a molecule that organisms can use to release the energy needed to survive

Tags

NGSS.MS-LS1-7

An indirect effect is:

• the result of one cause leading to an effect that causes one or more other effects

• the result of one cause stopping a desired effect

• the result of more than one cause leading to the death rate of a population

• when there is a direct relationship between one organism and the next

A scientist who studies ecosystems is known as:

• chemist

• biologist

• ecologist

• zoologist

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NGSS.5-LS2-1