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WorksheetsEcology Practice Questions
Total questions: 99
Worksheet time: 17hrs 30mins
Which role of protists has the most positive effect on maintaining the plant population in an ecosystem?
Protists are a major food source for animals
Protists produce approximately 75% of the oxygen on Earth
Protists decompose dead materials, returning nutrients to the soil
Protists found in the gut of animals assist in digestion
Saprophytes are fungi that feed on dead and decomposing organisms. They secrete enzymes that digest components of cell walls, such as cellulose and lignin.
Which statement explains why these fungi are an important part of the biogeochemical cycle?
Saprophytes perform gas exchange that assists the cellular activities of autotrophs.
Saprophytes extract minerals from living tissue to recycle them back into the soil.
Saprophytes transport nutrients through the xylem and phloem in autotrophs.
Saprophytes return organic material to the soil for use by living organisms.
A student researching bacteria concluded a report with the claim in the box.
Which statement correctly addresses the validity of the claim?
The claim is valid because many studies and experiments have shown that bacteria disrupt homeostasis.
The claim is invalid because there are many types of bacteria that help organisms maintain homeostasis.
The claim is invalid because only microorganisms such as viruses disrupt the health of organisms.
The claim is valid because bacteria cause disease.
Health professionals sometimes recommend nutritional supplements that contain a variety of species of bacteria to promote good digestive health. The product label for one of these supplements is shown.
Why does this type of bacteria-filled supplement benefit human health instead of causing illness?
Stomach acids and digestive enzymes kill the bacteria in this type of supplement, protecting the person against future infections by live organisms.
The human digestive system contains billions of beneficial bacteria that enhance digestion and nutrient absorption, synthesize vitamins, and help limit the growth of harmful bacteria.
These species of bacteria remove all the other species of microorganisms living in the human digestive system and ensure that no microorganisms survive to contaminate the body.
These bacteria are able to deactivate viruses that may inhabit the human digestive system and are used to protect against further viral infections.
Some fungi secrete substances that are toxic to bacteria that compete with them for food. Scientists have used their knowledge of this ability of fungi in order to produce which of the following substances?
Yogurt
Fertilizers
Plastic
Antibiotics
During secondary succession, which of these best describes why decomposing pioneer plants give way to larger, more complex plant species, such as hardwood trees?
Increased amounts of sunlight are able to reach the ground while the pioneer species are decomposing
Increased soil temperatures from decomposing pioneer species help tree seeds germinate more quickly
Increased amounts of decomposing pioneer species remove nutrients that tree seedlings need to grow and mature
Increased amounts of soil from decomposing pioneer species allow plants with more extensive root systems to become established
Grassland ecosystems in Texas have evolved to depend on periodic fires to return nutrients to the soil and encourage plant reproduction. Humans have prevented fires in many of these grassland areas, resulting in plant and animal communities with little diversity. Wildlife biologists often recommend purposefully starting fires called prescribed burns, which are monitored and controlled, in grassland ecosystems every 3 to 4 years. These biologists observe greater diversity in plant and animal life in the years following a prescribed burn. What natural processes are the biologists attempting to imitate?
Biomagnification
Succession
Population bottleneck
Species extinction
A small town in the piney woods of East Texas has a soccer field composed of native grasses. The soccer field is mowed once a week. What effect does continual mowing have on the ecology of the field?
Mowing increases the likelihood of nonnative species displacing native species.
Mowing increases the number of species found in the field.
Mowing causes different types of communities to form across the field.
Mowing maintains a low species diversity by inhibiting further succession
Enchanted Rock State Natural Area is located in Central Texas. Enchanted Rock is a dome of granite. The area contains four easily identifiable communities. The table describes characteristics of each type of community in the area.
A student studying primary succession should focus on which of these communities?
Open oak woodland
Mesquite grassland
Floodplain
Granite rock
An estuary collects sediments from teh ocean and rivers that feed into it. The sediments swirl around and then settle to form a medflat. Eel grass is then established on the mudflat. The ecosystem changes over time and ultimately develops into a salt marsh that contains mangrove trees. Which of the following is likely NOT involved in this example of ecological succession?
The rotting remains of plants add to the fertility of the soil
The soul becomes so fertile that eel grass is replaced by other plant species
The roots from plants help stabilize the sediment, keeping it in place
The concentration of salt becomes so high that all plant life is destroyed
The rocky material left behind by a retreating glacier forms what is called a moraine. When primary succession occurs on a moraine, which life-forms will help create the soil by breaking down bare rock?
Insects
Lichens
Grasses
Deciduous trees
During ecological succession, how does the growth of young hardwoods affect the organisms living in an ecosystem?
Grasses and low shrubs are unable to obtain the amount of light they need to survive, so there are small numbers of them
The trees provide shelter and food for a variety of mammals, insects, and birds
In Autumn, falling leaves provide a source of energy for decomposers such as fungi
All of these answer choices are correct
Which statement describes the differences in species diversity between an ecosystem beginning the process of primary succession and one beginning the process of secondary succession?
Species diversity is much greater in the ecosystems undergoing primary succession because that ecosystem is experiencing a longer period with a lack of competition for space
No differences in species diversity exist because both ecosystems initially lack living organisms
Species diversity is much greater in the ecosystem undergoing primary succession because the lack of soil provides a greater area for organisms to claim niches
Species diversity is greater in the ecosystem undergoing secondary succession because the soil already contains seeds and spores of various species
As ecosystems move through the stages of succession, the populations of organisms in them change. Which of the following describes the stage of succession likely to have the most species diversity?
A newly formed volcanic island
An agricultural field that has not been plowed for one year
A temperate forest that has. never been cleared by logging
A field that is regularly mowed
How do an increase in the organic matter in soil and an increase in soil depth affect the population of plants in an area?
Larger plants become the dominant species
Mosses replace flowering plants
Nitrogen-fixing bacteria kill young trees.
Grasses become diseased
The graph shows the changes in the number of species in an ecosystem. Which event was most likely the cause of the changes in species diversity in this ecosystem?
A large volcanic eruption
A flash flood
A small tornado
A migration of locusts
Surtsey is an island located south of Iceland. The island was formed by a volcanic eruption and first appeared in 1963. The table contains descriptions of changes in the population and diversity of species on Surtsey. Which of these lists the descriptions in the correct order of ecological succession on Surtsey?
I, II, IV, III
III, I, II, IV
IV, III, I, II
II, IV, I, III
The graph shows the basic changes in a forest community after a disturbance occurred. The information shown in the graph suggests that the changes in the forest community were caused by -
tree-leaf replacement after a storm
succession after a fire
repeated habitat destruction
decreased species diversity
The ocean sunfish is a large, flat fish that spends most if its time in deep water feeding mainly on jellyfish. Sunfish often have many species of copepods, small crustaceans, that bury their heads into the soft tissue of the sunfish. Sunfish will swim to the surface of the water and lie sideways, allowing seabirds to eat the copepods from their skin. Which list describes the types of relationships the sunfish has with other marine organisms?
Seabirds: mutualism
Jellyfish: predation
Copepods: parasitism
Seabirds: parasitism
Jellyfish: commensalism
Copepods: predation
Seabirds: predation
Jellyfish: mutualism
Copepods: commensalism
Seabirds: commensalism
Jellyfish: parasitism
Copepods: mutualism
Which of these best demonstrates mutualism between certain types of bacteria and humans?
Intestinal bacteria obtain nutrients from the gut and produce vitamin K used by humans
Bacteria become resistant to antibacterial medication that humans use for treatment
invasive bacteria at an area of injury produce toxins that damage healthy tissues of the human body
Bacteria in improperly prepared food is consumed by humans, causing food poisoning
In North American forests, two species of birds, nuthatchers and brown creepers, forage on the same trees for insects. Brown creepers feed on insects found near the bottom of the tree trunk, while nuthatchers feed on insects in the top part of the tree. The difference in foraging behavior most likely affects the nuthatchers and brown creepers by -
allowing the birds to avoid many types of predators
reducing competition between the birds for resources
preventing the birds from interbreeding with each other
establishing dominance between the birds for nesting sites
A partial Texas food web is shown. The populations of which organisms will most likely increase as a result of a disease that suddenly reduced the population of Texas horned lizards?
Grasses and ants
Ants and grasshoppers
Grasshoppers and Texas cottonmouths
Texas cottonmouths and red-shouldered hawks
A biomass pyramid of an ecosystem is shown. Which statement provides the best explanation for the difference in biomass of organisms found at each trophic level?
Organisms at higher trophic levels have less energy available to them than organisms at lower trophic levels
Organisms are higher trophic levels require smaller habitats than organisms at lower trophic levels
Organisms at lower trophic levels provide less energy than organisms at higher trophic levels
Organisms at lower trophic levels outcompete organisms at higher trophic levels
The table lists some organisms found in a swamp ecosystem and their sources of energy. When constructing an energy pyramid of the swamp ecosystem, which of these would be placed at the top of the pyramid?
Grass carp
American alligator
Eastern mud turtle
Great blue heron
A partial meadow food web is shown. Based on this food web, which organisms are direct sources of energy for secondary consumers?
Aphid
Bird
Rabbit
Ladybug
Fox
Dragonfly
Frog
Butterfly
Berries
Mouse
Snake
Hawk
The energy pyramid below shows the energy made available by producers. Based on the energy flow between trophic levels in an energy pyramid, how much energy would be expected to be found at the secondary consumer level in this pyramid?
100 joules
500 joules
1000 joules
50 joules
The Texas blind salamander lives in the Edwards Aquifer region around San Marcos. The table lists some of the organisms that live with the salamander in this environment and their food sources. In an energy pyramid for these aquifer cave dwellers, which of the following would be placed at the bottom?
Snails
Blind shrimp
Protozoa
Texas blind salamanders
What would be the most likely effect of a wildfire that burned a large area of a forest?
More sugars and starches would be available for animals in the area.
The availability of fossil fuels for use by industries in the area would be reduced.
Less carbon dioxide would be removed from the atmosphere in the area by plants.
An increase in animal respiration would increase the release of carbon dioxide in the area.
Which of the following is most likely to cause the greatest disruption to an ecosystem?
Emptying an aquarium containing non-native species into a local waterway
Cutting down a small cedar tree to make holiday decorations
Cleaning the windshield of a car with an alcohol-based glass cleaner
Mowing the lawn in a city park
Many years ago, a volcanic eruption killed many plants and animals on an island. Today the island looks much as it did before the eruption. Which statemnt is the best possbile explanantion for this?
Altered ecosystems regain stability through the evolution of new plant species
Destroyed environments can recover as a result of the process of ecological succession.
Geographic barriers prevent the migration of animals to island habitats
Destroyed ecosystems always return to their original state
A fire burns an oak forest down to bare ground. Over the next 150 years, if the climate remains constant, this area will most likely
remain bare ground
return to an oak forest
become a rain forest
become a wetland
What impact do the amounts of available energy, water, and oxygen have on an ecosystem?
They act as limiting factors
They are used as nutrients
They recycle the residue of dead organisms
They control environmental temperature
Nutritional relationships between organisms are shown in the diagram below. The mouse population would most likely decrease if there were
an increase in the frog and tree populations
a decrease in the snake and hawk populations
an increase in the number of decomposers in the area
a decrease in the amount of available sunlight
In the diagram below, what does X most likely represent?
autotrophs
herbivores
decomposers
carnivores
Which diagram best illustrates the relationship between humans (H) and ecosystems (E)?
1
2
3
4
Base your answers on the accompanying passage and your knowledge of biology.
Which group contains decomposers?
A
B
C
D
Base your answers on the accompanying passage and your knowledge of biology.
Which food chain best represents information in the passage? (Remember the arrow points in the direction that the energy flows prey > predator)
lupine > Karner Blue larvae > wasps
wasps > Karner Blue larvae > lupine
Karner Blue larvae > lupine > wasps
lupine > wasps > Karner Blue larvae
What would most likely happen if most of the bacteria and fungi were removed from an ecoystem?
Nutrients resulting from decomposition would be reduced
Energy provided for autotrophic nutrition would be reduced.
The rate of mutation in plants would increase
Soil fertility would increase
The graph below shows the effect of moisture on the number of trees per acre of five tree species. Which observation best represents information shown in the graph.
All five species grow in the same habitat
The American elm grows in the widest range of moisterure conditions
Red oaks can grow in wetter conditions than black willows.
Sugar maples can grow anywhere black oaks can grow.
When habitats are destroyed, there are usually fewer niches for animals and plants. This action would most likely not lead to a change in the amount of
biodiversity
competition
interaction between species
solar radiation reaching the area
The removal of nearly all of the predators from an ecosystem would most likely result in
an increase in the number of carnivore species
a decrease in new predators migrating into the ecosystem
a decrease in the size of decomposers
an increase in the number of herbivores
Ten breeding pairs of rabbits are introduced onto an island with no natural predators and a good supply of water and food. What will most likely happen to the rabbit population?
It will remain relatively constant due to equal birth and death rates
It will die out due to an increase in the mutation rate.
It will increase until it exceeds carrying capacity.
It will decrease and then increase indefinitely.
The ecological niches of three bird species are shown in the diagram below. What is is the advantage of each bird species having a different niche?
As the birds feed higher in the tree, available energy increases
More abiotic resources are available for each bird.
Predators are less likely to feed on birds in a variety of locations
There is less competition for food
Which statement best describes how bacteria recycle matter in an ecosystem?
Bacteria are producers that create energy for second-order consumer.
Bacteria produce toxins to prevent the growth of invasive species.
Bacteria cause diseases that limit the reproduction of organisms in a population.
Bacteria are decomposers that help to transfer organic material to the soil.
A student sets up a compost bin outdoors. Inside the bin microorganisms convert the student's vegetable and paper scraps into rich fertilizer. Which of the following best describes the role that these microorganisms play in natural habitats?
The microorganisms help balance the numbers of producers and consumers.
The microorganisms help keep nutrients cycling through the ecosystem.
The microorganisms turn solar energy into sugars.
The microorganisms function as autotrophs.
Hydrothermal vents form deep in the ocean when iron-rich magma is released from openings on the seafloor. These vents spew extremely hot water (400 degrees Celsius) mixed with methane and sulfur. Bacteria that thrive in this hostile environment form the base of a food chain that leads to colonization by tube worms, mussels, and many other life-forms. When a hydrothermal vent becomes inactive and cold, the bacterial community that lives in the hot fluid methane and sulfur dies out. Which organisms most likely succeed the original community in this ecosystem?
Cold-tolerant bacteria that feed on sulfur and iron in the vents.
Giant kelp that use sulfur in photosynthesis.
Fish that do not need oxygen for cellular respiration.
Ocean mammals that tolerate cold and act as top predators in the food chain.
Sand dunes along the coast are formed of bare sand. Eventually, grasses take root on the dunes. Over time, larger plants such as shrubs and trees are able to grow at the edge of the sand dune ecosystem. This gradual change in plant communities of a sand dune ecosystem can result in -
reduced symbiotic relationships between producers and bacteria
reduced energy absorption by consumers
greater erosion rates
greater species diversity
During secondary succession, which of these best describes why decomposing pioneer plants give way to larger, more complex plant species, such as hardwood trees?
Increased amounts of sunlight are able to reach the ground while the pioneer species are decomposing.
Increased soil temperatures from decomposing pioneer species help tree seeds germinate more quickly.
Increased amounts of decomposing pioneer species remove nutrients that tree seedlings need to grow and mature.
Increased amounts of soil from decomposing pioneer species allow plants with more extensive root systems to become established.
In an experiment, two plants are grown together for a time and then separated. Plant 2 is a parasite of Plant 1.
Which graph best predicts the growth of Plant 1 and Plant 2 during the experiment?
Four common relationships between organisms are listed in the box.
Which statements best describe these relationships?
Relationships 1 and 4 are examples of mutualism.
Relationship 2 is an example of commensalism.
Relationship 3 is an example of parasitism.
Relationships 1 and 2 are examples of commensalism.
Relationships 3 and 4 are examples of mutualism.
Relationship 1 is an example of commensalism.
Relationships 2 and 4 are examples of mutualism.
Relationship 3 is an example of predation.
Relationships 1, 2, and 4 are examples of mutualism.
Relationship 3 is an example of parasitism.
A student performed an investigation in which two ivy plants were planted in two separate containers. One of the containers had earthworms mixed in with the soil, and the other container had soil and no earthworms. The plants were given the same amount of water and exposed to the same amount of sunlight. The student observed that after several weeks of growth, the plant exposed to earthworms appeared to be healthier and exhibited more growth. To conclude that the relationship between the plant and the earthworm is an example of mutualism, the student must perform follow-up investigations that do which of the following?
Determine whether the earthworms damage the soil in any way.
Determine whether the earthworms benefit from being with the plant.
Determine whether the water given to the plant is unpolluted.
Determine whether the other plant in the investigation suffers as a result of not being exposed to earthworms.
Parrotfish are herbivores that are found in coral reefs. To escape predators, a parrotfish will graze with a rabbitfish, which has venomous spines at the end of its pelvic fins. The rabbitfish does not benefit from the relationship. Which type of relationship do the parrotfish and the rabbitfish have in the coral reef environment?
Commensal
Mutualistic
Predator-prey
Parasitic
Bats eat insects that damage crops and mosquitoes that are vectors for disease. One million bats can eat several tons of insects per night, saving billions of dollars in pesticides yearly. Agricultural and public health scientists are concerned about the spread of white-nose syndrome (WNS). WNS is a result of a fungus that can infect cave-dwelling bats. While bats hibernate during winter months, the fungus covers the bats' face and wings. WNS has a near 100% mortality rate, and 5.7 million bats have dies since the discovery of the fungus in 2006. Many scientists are searching for ways to protect these bats. The relationship between this fungus and bats can best be defined as -
commensal, because the bats provide a surface for the fungus to grow
parasitic, because the fungus obtains nutrients and shelter from the bats
competitive, because both organisms use caves as shelter during the winter.
mutualistic, because the relationship involves two distinct species living together
In any environment or ecosystem, organisms can have several different types of relationships. Three types of relationships are described in the box.
Which of these correctly describes the relationships between the organisms?
X: mutualism
Y: parasitism
Z: commensalism
X: commensalism
Y: mutualism
Z: parasitism
X: parasitism
Y: commensalism
Z: mutualism
X: commensalism
Y: parasitism
Z: mutualism
Brazil nuts are tall canopy trees that make up a large portion of the Amazon rain forest. They produce large grapefruit-sized seedpods. The agouti, a ground-dwelling rodent, has teeth strong enough to open the tough seedpods. While the agouti eats some of the tree's seeds, it also buries caches in various spots on the rain forest floor.
Why is the agouti important tot he rain forest ecosystem?
It eats and disperses the trees' seeds.
It eats the trees' excess seeds and prevents other animals from doing so.
It cleans the rain forest floor of debris, allowing for easier motility.
It prevents the trees' seeds from rotting on the rain forest floor.
The acacia ant lives in the bullshorn acacia plant, as shown in the box.
The acacia ant nests and feeds in the plant's hollow thorns. The ant helps protect the bullshorn acacia by attacking insects and grazing animals that come near the plant. The relationship between the acacia ant and the bullshorn acacia is an example of which of the following?
Commensalism
Mutualism
Neutralism
Parasitism
A native species and non-native species are competing for resources within the same ecosystem. The non-native species is more likely to survive than the native species in which of the following situations?
Both the native and the non-native species thrive on the same food source.
The native species is immune to certain pathogens in the ecosystem.
Predators prey on both native and non-native species.
The non-native species has no natural enemies in the ecosystem.
The defenses of two flightless birds that live in different habitats are shown.
How do the wings of the Gentoo penguin and the legs of the common ostrich provide an advantage in their habitat?
Allows them to find prey
Allows them to escape from predators
Allows them to control their body temperature
Allows them to be camouflaged in their environments
The trophic pyramid is a triangular shape because
90% of energy is lost to heat, movement, and survival, and only 10% of energy goes to the next level
People see the top of the pyramid so it is important to know the keystone species.
10% of energy is lost to heat, movement, and survival, and only 90% of energy goes to the next level
the top of the pyramid is the pinnacle organism of an ecosystem
The food web shows
many possible interactions and feeding relationships beween the organsims in the ecosystem
a nice picture of what lives in the ecosystem
the symbiotic relationships
the keystone species
What is the difference between a Trophic Pyramid and Food Web?
A Trophic Pyramid shows the energy & mass available, but the food web shows directly who eats who.
A food web shows the mass & energy available, but the Trophic Pyramid shows directly who eats who.
A food web is so pretty to look at.
A trophic pyramid is so beautiful.
Based on the food web shown above, which of the following is most likely responsible for the rabbit population trend as shown in the graph?
increase in amount of grass
decrease in amount of grass
overpopulation in squirrel population
decrease in hawk population
Which organisms are predators of the piping plover? (Click all that apply)
Foxes
Dogs
Cats
Raccoons
Great horned owls
If the population of Piping Plovers decreased, what would likely happen to the population of foxes?
The population of foxes would definitely increase
The population of foxes would definitely decrease
The population of foxes might decrease because they eat Piping Plovers, but if there are enough other foods for the fox, then the population may be unaffected.
Secondary succession occurs -
after a forest fire wipes out a flourishing ecosystem, leaving it with only soil and rock.
after a volcano erupts, leaving a flourishing ecosystem covered in ash and rock.
when lichens and mosses break down rocks into soil, eventually leading to a developing ecosystem.
when humans cut down trees to develop land into a shopping mall.
If the primary productivity of an ecosystem increases, what could be the resulting population change in the organisms that occupy this area?
population size will increase
population size will decrease
population size will remain unchanged
population size will fluctuate more
Match the type of survivorship curves with the appropriate descriptions below:
Type 1: survival is high at an early and middle age and decreases into old age. Type 2: survival remains the same life, implying that their mortality rate remains constant at every age. Type 3: survival is low in the early ages and continues to increase throughout life.
Type 1: survival is low in the early ages and continues to increase throughout life. Type 2: survival remains the same life, implying that their mortality rate remains constant at every age. Type 3: survival is high at an early and middle age and decreases into old age.
Type 1: survival is low in the early ages and continues to increase throughout life. Type 2: survival is high at an early and middle age and decreases into old age. Type 3: survival remains the same life, implying that their mortality rate remains constant at every age.
Type 1: survival is high at an early and middle age and decreases into old age. Type 2: survival is low in the early ages and continues to increase throughout life. Type 3: survival remains the same life, implying that their mortality rate remains constant at every age.survival is low in the early ages and continues to increase throughout life.
What would likely occur if you introduce an invasive species of insect that destroy most (possibly all) of the grasses?
the primary consumers that feed on the grass may decline as a result, causing the secondary consumers to crash, etc.
nothing will happen, more grass will grow in its place and everything will carry on as normal.
primary consumers will increase in number to counteract the loss of producers in the ecosystem
all organisms at higher trophic levels will increase as a direct result of this change in producer population.
If the grass starts out with 10,000 J of energy...how much of the original energy is available to the snake in this food chain?
1,000 J
100 J
10 J
1 J
0.1 J
Which of the following is an example of an abiotic factor on a biotic factor?
death of trees causes soil erosion
a drought causes a herd of sheep to migrate to another area
a wolf population hunts a rabbit population
a fire results in better soil quality
A hummingbird receives a nectar food reward and the plant benefits by having its genetic material carried to another flower to increase genetic diversity through sexual reproduction. What type of relationship is this?
mutualism
commensalism
predator-prey
parasitoid
This is an unlabeled predator-prey relationship graph. Which one represents the prey?
the line that gets up to ~80 individuals
the line that gets up to ~40 individuals
both are equally likely
In this foodweb interspecific competition occurs between
dolphins and otters for pollock
eel grass for bacteria and little schools of fish
dolphins and seals for herring
ocra for dolphins and seals
Use the picture to answer the following question:
What is a keystone species?
A species that helps to hold an ecosystem together
A species that lives in or around rocks
Keys and stones have nothing to do with ecology
A keystone isn't a living thing, it's just a stone
Why is most of the energy at the bottom of the pyramid?
Because producers use the most energy
Because consumers use the most energy
Because consumers make the most energy
Because producers make the most energy
If the fox was removed from the ecosystem which other organism would be affected?
The grasshopper would decrease
The hawk would decrease
The trees would increase
The chipmunk would decrease
Mistletoe is an evergreen shrub that can produce most
of its own food. Often, mistletoe can be found living
on trees and taking water and nutrients away from the
tissues of the trees. The relationship between
mistletoe and trees is an example of
consumer/herbivore
predator/prey
scavenger/decomposer
parasite/host
If several species of carnivores are removed from an ecosystem, the most likely effect on the ecosystem will be:
An increase in the kinds of autotrophs
A decrease in the number of abiotic factors
A decrease in stability among populations
An increase in the rate of succession
Why is a mushroom considered a heterotroph?
It creates different types of food.
It makes food through photosynthesis.
It makes food through chemosynthesis.
It obtains nutrients from its environment.
The common brushtail possum is a marsupial native to Australia. This possum was introduced to New Zealand where it had no natural predators and had an abundant food supply. Which of these likely occurred a few years after the introduction of this possum to New Zealand?
The possums became extinct.
The possums developed shorter life spans.
The possum population grew to a larger size.
The possum population evolved into a different species.
An animal population decreases from 800 individuals to 600 individuals. Which of the following could explain this change in population size?
The population size of the animal’s predator increased.
The emigration rate of the animals from the population decreased.
The number of breeding pairs in the animal’s population increased.
The number of species competing with the animal for food decreased.
A biologists compares how different ecosystems undergo succession. She divides the series of events that happen during primary and secondary succession into three different stages. Which feature might be used to distinguish secondary succession from primary succession?
the lack of pioneer species in the second stage
the presence of pioneer species in the final stage
the presence of trees and large plants in the final stage
the presence of soil and organic matter in the first stage.
After a volcano erupts and destroys an ecosystem, a few organisms are able to begin growing from the decaying organic matter left behind. What do we call those organisms that are able to grow in little or no soil that first appear?
adaptors
pioneer species
non-vascular plants
decomposers
A builder is proposing a new housing development in an area of western Massachusetts. Construction of the housing development will destroy the wetland habitat in the area.
Which of the following would be the most likely consequence of the wetland’s destruction?
The wetland plant species would disperse to adjacent meadow habitats.
The populations of wetland animals would be unable to survive in that area.
The wetland animal species would survive by interbreeding with non-wetland species.
The populations of wetland plants would evolve to disperse seeds by wind rather than water.
Mullet are local estuarine fish that move in schools and feed on plankton and plant matter. Natural predators of the mullet include spotted sea trout, sharks, pelicans and dolphins. The graph above shows how the number of mullet in an area has changed over time.
Based on the data, one student concludes that a new predator was introduced into the area during this time period. Which of the following is a likely alternate explanation for the change in the mullet population
mullet prey increased in the area
mullet parasites decreased in the area
the temperature of the area increased
the amount of aquatic plants in the area decreased
How does the predator-prey relationship affect a population?
The predators and prey are in competition with each other.
Usually either the predator or the prey will become extinct.
The predator species usually has exponential growth.
The relationship controls the population size of both species.
The pH of the water in several lakes in Norway and Sweden had decreased to below 5.0 due to an increase in acid rain. Which of the following is most likely to happen in these lakes?
the decline of several fish populations.
an increase in numbers of fish
an increase in the amount of primary producers
increased predator-prey relationships
The number of pythons found throughout Everglades National Park has increased in recent years. These huge snakes are not native to Florida and are believed to have been released into the wild by pet owners. Wildlife biologists have initiated attempts to capture and remove these pythons. Which statement best explains the biologists' reasons for removing these pythons from the Everglades?
The pythons could upset the territorial boundaries of native organisms.
The pythons could adapt to overcome diseases common to native snakes.
The pythons could prey on native organisms and cause native population to decline.
The pythons could begin to interbreed with native snakes and produce a more successful species.
A team of ecologists observed feeding patterns of several populations in the desert. The energy pyramid shown above depicts the feeding patterns the ecologist observed.
Which of the following best explains the difference in the amount of available energy in the trophic levels of the desert ecosystem?
There is less energy available in the producers because their tissues are less dense than those at higher trophic levels.
There is more energy available in the second trophic level because less energy is needed for hunting compared to the higher trophic levels.
There is more available energy in the birds of prey because they have greater muscle mass for storing energy than organisms in lower trophic levels have.
There is less available energy in the fourth trophic level because of the loss of energy through metabolism in each of the lower trophic levels.
A diagram of a food web is shown above.
Which organism receives the least amount of energy from the producers?
hawk
rabbit
grasshopper
mouse
The diagram above shows the cycling of nutrients in an ecosystem.
The removal of which of the following groups would cause an immediate decrease in the amount of energy flowing through the
producers
consumers
decomposers
inorganic nutrients
Salt water is an abundant resource but unusable for irrigation and drinking. As demands on freshwater sources increase, the use of desalination processes to remove salt from ocean water is increasing. A concern of desalinating water is the large amounts of recovered salts that are returned to the ocean. Which of the following describes the most likely impact of desalination on the surrounding ocean environment?
Methane gas would pollute the ocean environment as shoreline organisms begin to die and decay.
Alteration in ocean salt levels would cause loss of species and unbalanced populations in marine food webs.
Nonrenewable resources in the ocean environment would become depleted and upset the ecosystem's balance.
Increased levels of salts and minerals in the ocean would result in overpopulation of marine bivalves due to strengthened shells.
DDT and other pesticides used over 50 years ago are still affecting the environment today. Scientists have found these substances in recent glacier runoff. Glacier runoff occurs during the summer, when precipitation that has fallen on glaciers during the winter is released. Ice layers from existing glaciers have been analyzed. The results of this analysis show that the concentrations of DDT and other pesticides were highest about 10 years after the use of these substances was banned.
This information shows that
DDT and other pesticides cause glacier runoff during the summer.
it takes humans over 50 years to analyze a glacier.
precipitation helps to break down pesticides.
the decision of one human generation may have an impact on future generations.
The northern elephant seal was almost hunted to extinction in the 1800s. By the late 1890s, approximately one hundred seals were left, reducing the gene pool of the population. What will be the consequence of this reduction?
Competition within the population will increase.
The surviving elephant seals will be better able to adapt.
Inbreeding will be less frequent among the remaining population.
The elephant seals will be more vulnerable to environmental change.
For which of the following resources might animals compete?
Food
Water
Space/Territory
Mates
What best describes the term succession?
rapid changes that create an ecosystem overnight
gradual changes over time to fully create or restore and ecosystem
forest with the tallest trees
the rate species produce offspring
