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WorksheetsBiodiversity
Total questions: 27
Worksheet time: 19mins
What is the role of the producers in a stable ecosystem?
to manufacture food if the decomposers begin to die out
to supply the ecosystem with energy
to remove nitrogen to form glucose and dead organic matter
to filter wastes out of the environment
A food chain includes at least two trophic levels. Which tropic levels are these?
producers and top consumers
consumers and decomposers
primary and secondary consumers
producers and primary consumers
Which statement best summarizes what would happen to an ecosystem if people destroyed most of its decomposers by using chemicals to control bacteria and fungi?
Producers would begin to die out.
Dead organisms would pile up and not decay.
Many nutrients would stop recycling through the ecosystem.
The number of producers would increase dramatically, leading to population growth among consumers.
Over time, a grassy field becomes dryer, and the most common kind of plant becomes shorter and tougher then the original grass. What will happen in the ecosystem as a result of this change?
The primary consumers will change to ones that eat the new kind of grass.
Nutrients will not be as easily available to consumers because the field has changed.
The overall population of producers will decrease.
Consumers will migrate to other areas.
Due to a viral disease, the entire population of wolves-secondary consumers- in an island ecosystem disappears. The number of primary consumers- rabbits- will increase. What will happen to the populations of producers?
They will increase, because there are fewer secondary consumers.
They will stay the same, because nothing that happens to consumers affects them.
They will decrease, because there will be more primary consumers.
They will increase, because more nutrients will be available from decomposers.
The chart above shows an increase in population over time. Which of the following could best explain this increase?
decreased resource rate
decreased growth rate
decreased death rate
decreased immigration rate
In many cities, parks have signs asking people to not feed the pigeons. The most likely reason for decreasing the bird's food supply is that it may
increase the birds' death rate
force them to emigrate
make it unnecessary for park employees to clean up after pigeons.
replace pigeons with songbirds.
In a given area, a population is a group of organisms of the same
species.
family.
ecosystem.
habitat.
Many lakes in the United States have received large amounts of nutrients, such as nitrogen and phosphorus, as a result of pollution from farms and industry. This pollution causes rapid and massive increases in some lakes' algae population. This gradually depletes lakes' oxygen supply, killing many organisms. What is the most logical explanation for the rapid growth of algae?
The increased nutrients led many organisms to emigrate.
The increased nutrients supported the population growth of algae.
The increased nutrients allowed algae to out-compete other species.
The increased nutrients caused algae to immigrate.
Suppose the deer population in a local forest preserve is much larger than last year. There have been no major changes in food supply, and hunting is forbidden. Which of the following best accounts for the population increase?
increased emigration and increased birth rate
decreased emigration and increased death rate
increased immigration and increased birth rate
increased immigration and increased death rate
Compared to ecosystem changes resulting from human activity, most natural changes in ecosystems are predictable because they
evolve over a long time.
are random in their effect.
affect population size but not resource availability.
occur on a seasonal basis.
The table above comes from a hypothetical census of organisms living in four regional ecosystems. Which ecosystem has the most biodiversity?
Rain forest
Tundra
Scrubland
Woodlands
Which of the following terms best describes the term biodiversity?
the number of organisms inhabiting tropical rain forests
the range of habitats within a geographic area
the variety of species living in a ecosystem
the abiotic and biotic factors in an ecosystem
Compared with ecosystems that have less biodiversity, ecosystems high in biodiversity have more
rainfall.
stability.
abiotic factors.
human disturbances.
Which term best describes the area where an organism lives and all of the biotic and abiotic factors affecting it?
community
population
biodiversity
habitat
Elephant are considered an important species in east Africa. During droughts, they dig deep holes in dry riverbeds, and the holes fill up with water. These holes are then used by all other animals in the area. Which of the following most accurately describes how the loss of elephants would affect this ecosystem?
Biodiversity would increase, as more species evolved.
Biodiversity would remain the same, but population sizes would increase.
Biodiversity would decrease, since few species could tolerate living with less available water.
Biodiversity would not change, although there would be increased predation by lions.
Almost 90 percent of the energy transferred up the food chain is lost as heat between trophic levels. The energy that is not lost as heat is
recycles by decomposers.
recycled back to producers.
incorporated as biomass at each level.
used to provide energy for chemosynthesis.
Which of the following best illustrates the feeding relationship between organisms in a community?
energy pyramid
decomposers
Hardy-Weinberg equilibrium
food web
Producers are always at the base of a food chain or food web. The best explanation for this is
producers are stronger than consumers.
producers manufactured the food that supports the entire ecosystem.
producer populations are less important than consumer populations.
producers grow on the ground or on the sea floor.
What is biodiversity?
the range of traits within members of the same population
the amount of genetic variation within a species
the reason it is difficult to define an ecological community
the range of species present in an ecosystem
Human sometimes kill giant tritons in order to collect their attractive spiral shells.
If humans kill most of the giant tritons in a coral reef, the coral population will most likely
decrease due to a decrease in the parrot fish population.
increase due to an increase in the parrot fish population.
increase due to a decrease in the crown-of-thorns sea star population.
decrease due to an increase in the crown-of-thorns sea star population.
What would most likely happen if the rabbit population decreased as a result of another predator being introduced to the food web?
The fox population would decrease.
The food web would not be affected.
The bird population would increase.
The spider population would decrease.
What would most likely result if nitrogen-fixing bacteria in an area were destroyed.
Vegetation in the area would grow at a faster rate.
Vegetation in the area would grow at a slower rate.
Vegetation in the area would not affected.
Vegetation in the area would find other nutrient sources.
Which statement best explains what is happening at point A?
Population growth decreases as individual crabs get older.
The population is stabilizing as it approaches carrying capacity.
Destruction of habitat is causing a decline in the population of the crabs.
The introduction of a new predator is causing a decline in population growth of the crabs.
An ecosystem has a stable population of white-tailed deer. What is the most likely outcome if a new species of deer that competed for the same resources were introduced?
The white-tailed deer population would increase.
The producer population would decrease.
The white-tailed deer population would not be affected.
The predator population would decrease.
A forest area is being harvested for specific types of plants, causing a reduction of resources for organisms. The organisms most likely to become extinct as a result of this activity is
one with a specialized diet.
one with a high rate of reproduction.
one that feeds from a variety of sources.
one that has a great amount of genetic variation.
Zebra mussels were first discovered in the Great Lakes thirty years ago and have since spread to lakes throughout the region. Zebra mussels reproduce quickly and have few natural predators.
What will most likely happen to other native mussel species in the Great Lakes region?
Native species will begin to interbreed with zebra mussels.
Native species populations will decrease in areas with large zebra mussel populations.
Individuals of the native species will mutate to become more sililar to zebra mussels.
Individuals of the native species will mutate to become less similar to zebra mussels/.
