Pop Basics
What is a population?
A. All the different species living on Earth.
B. A group of organisms of the same species living in the same area.
C. A group of nonliving things in an environment.
B. A group of organisms of the same species living in the same area.
Which event directly increases a population?
A. Birth
B. Death
C. Moving away
A. Birth
What is a food web?
A. A single animal's life cycle
B. Connected food chains showing feeding relationships
C. A map of where water is found
B. Connected food chains showing feeding relationships
What is an energy storage molecule in animals?
A biological compound that holds chemical potential energy inside an animal's body so it can survive, move, hunt, find a mate, stay warm, and reproduce.
Which change could make it harder for organisms to survive?
A. More available food
B. Pollution in their habitat
C. A suitable amount of water
B. Pollution in their habitat
A population has 150 rabbits. During the year, 40 are born and 25 die. No rabbits move in or out. What is the new population?
165
A frog population starts at 80. During a season, 35 frogs are born, 20 die, and 10 move in. What is the new
population size?
105
Mice eat seeds, and owls eat mice. A disease causes the mouse population to decrease. What may happen
to the owls?
A. Owls may decrease because they have less food
B. Owls increase because fewer mice eat seeds
C. Owls stay unchanged because they do not eat seeds
A. Owls may decrease because they have less food
Two rabbit populations live in grasslands. One area has plentiful healthy plants; the other has little plant
growth because of drought. Why might the populations change differently?
A. Both populations must grow at the same rate
B. Rabbits in the dry area may have less energy available for survival and reproduction
C. Rabbits no longer need food energy during drought
A. Both populations must grow at the same rate
A cold winter causes many young deer to die, while the number of births stays the same. What is the likely
effect?
A. The population may decrease because more individuals are dying
B. The population must increase because births stayed the same
C. The population cannot change unless births change
A. The population may decrease because more individuals are dying
A population of 500 fish stays close to 500 for 5 years, even though fish are born and die. Which explanation best fits this pattern?
A. Births and deaths balance each other over time
B. No fish reproduce or die
C. Fish stop needing resources
A. Births and deaths balance each other over time
A bird population has 60 births, 85 deaths, 20 birds moving in, and 5 moving out. What happens to the
population overall?
A. It increases by 10
B. It decreases by 10
c. It decreases by 25
B. It decreases by 10
Small fish eat aquatic insects, and large fish eat small fish. If aquatic insects decrease, what is a likely chain
of effects?
A. Small fish increase, then large fish increase
B. Small fish may decrease, reducing the food available to large fish
C. Large fish increase because there are fewer insects
B. Small fish may decrease, reducing the food available to large fish
In this food chain, plants ® grasshoppers ® frogs, the plant population decreases. What may happen to the
frog population?
A. Fewer plants may mean fewer grasshoppers and less food for frogs, possibly lowering frog numbers
B. Frogs increase because there are fewer plants
C. Frogs stay stable because they do not eat plants directly
B. Frogs increase because there are fewer plants
Frogs in a wetland eat insects, and herons eat frogs. Pollution causes the insect population to decrease.
What is a possible result?
A. Frogs may decrease from having less food, and herons may later decrease if fewer frogs are available
B. Frogs and herons both increase because there are fewer insects
C. Only insects change because pollution cannot affect other populations
A. Frogs may decrease from having less food, and herons may later decrease if fewer frogs are available
ns
What is one reason a population might decrease even when some individuals are being born?
A. Births are greater than deaths
B. Deaths and individuals moving out exceed births and individuals moving in
C. Every individual has enough food
B. Deaths and individuals moving out exceed births and individuals moving in
If the number of births stays the same but deaths increase, what is the most likely result?
A. The population grows faster
B. The population may decrease or grow more slowly
C. The population cannot change
B. The population may decrease or grow more slowly
Why can a change in one species affect several other species in a food web?
A. Species depend on one another for food and energy
B. Every species eats the same food
C. Food webs prevent populations from changing
A. Species depend on one another for food and energy
Why can limited food cause a population to grow more slowly?
A. Organisms may have less energy to survive and reproduce
B. Limited food always causes more births
C. Food availability has no effect on populations
A. Organisms may have less energy to survive and reproduce
How might a disease affect a population?
A. It can increase deaths and cause the population to decrease
B. It always increases the amount of food available
C. It prevents all future population changes
A. It can increase deaths and cause the population to decrease
Two populations of the same species live in different areas. What would be needed to compare how their
sizes changed over time?
A. Their population counts from more than one time point
B. The color of the organisms
C. The name of each area only
A. Their population counts from more than one time point
A population gains 18 individuals through births and immigration and loses 18 through deaths and
emigration. What is the net change?
A. An increase of 36
B. A decrease of 18
C. No net change
C. No net change
A predator population increases and consumes more of its prey. If the prey population then falls, what could
happen to the predator population later?
A. It must keep increasing
B. It may decrease because less prey is available
C. It will no longer need energy
B. It may decrease because less prey is available
If a population uses resources faster than those resources can be replaced, what may happen over time?
A. Resources will become unlimited
B. Resource availability may decline and affect the population
C. The population is guaranteed to double
B. Resource availability may decline and affect the population
A habitat loses much of its water and plant life. Which outcome is most reasonable for animals living there?
A. Their populations may be affected because important resources are reduced
B. Their populations will all increase
C. They will no longer depend on their habitat
A. Their populations may be affected because important resources are reduced