WorksheetsBiology Keystone Ecology
Total questions: 22
Worksheet time: 51mins
A species of snapping turtles has a tongue that resembles a worm. The tongue is used to attract small fish. Which best describes the interaction between the fish and the snapping turtle?
predation
symbiosis
parasitism
competition
Which set of ecological organization levels is most likely to contain the largest variety of species?
multiple biomes in a biosphere
multiple ecosystems in a biome
multiple individuals in a population
multiple populations in a community
An aye-aye is a small nocturnal lemur that weighs about four pounds. This endangered species is found in Madagascar, a large island off the east coast of southern Africa. The main food for aye-ayes is larvae that live in wood. Aye-ayes find the larvae by tapping on tree branches. They also eat nuts and fruit. Aye-ayes spend most of their time alone. Each animal occupies about 15 acres and marks the territory, which alerts other aye-ayes of the boundary.
For the aye-aye species, what is most likely the primary value of individuals living alone?
decreased space needs for the species
increased survival rates with habitat loss
reduced competition for natural resources
greater genetic variability within the species
Which energy transfer most likely occurs between organisms in the food web?
from owl to fox
from rabbit to fox
from bird to grass
from mouse to grasshopper
Which description is the best example of a population?
all of the red foxes in a forest
all of the red foxes and gray foxes in a forest
all of the organisms in a forest
all of the organisms in every forest
Ash from a volcanic eruption decreases the amount of available solar energy for a region. Which statement describes how a decrease in available sunlight will most likely affect ecosystems of this region?
Producer populations will decrease, causing a decrease in consumer populations.
Producer populations will decrease, causing an increase in consumer populations.
Decomposer populations will increase, causing a decrease in consumer populations.
Decomposer populations will increase, causing an increase in consumer populations.
Scientists observed that the populations of top-level consumers in a particular ecosystem were rapidly decreasing. Further studies revealed that there was also a decline in producer productivity. Which other changes did the scientists most likely observe in the ecosystem?
increased producer diversity
decreased population size at all levels
decreased primary consumer populations only
increased primary and secondary consumer diversity
Which sequence correctly describes the flow of energy between organisms in the marine food web?
from seals to penguins to krill
from whales to krill to small fish
from sea birds to seals to penguins
from small fish to penguins to seals
In Pennsylvania, a nonnative plant called stiltgrass out-competes native plants in many forest ecosystems. Which statement best describes how the spread of stiltgrass negatively affects native herbivores?
Stiltgrass stops the life cycles of native herbivores.
Stiltgrass reduces the size of the native plant populations.
Stiltgrass increases the flow of energy through the ecosystem.
Stiltgrass attracts other nonnative plants to the forest ecosystem.
Use the list below to answer the question.
Observations
• two grey wolves • five moose • several species of conifer trees • large granite rock • shallow pond
A student wrote several observations in a field notebook. Which term best classifies all of the student’s observations?
population
food chain
ecosystem
community
Which statement best describes a contribution that decomposers make to an ecosystem?
They reduce the atomic mass of carbon atoms.
They increase the recycling of carbon-containing molecules.
They reduce the total number of carbon atoms in the atmosphere.
They increase the total number of carbon nuclei within the atoms.
A researcher observing an ecosystem describes the amount of sunlight, precipitation, and type of soil present. Which factors is the researcher most likely describing?
biotic factors in a forest
biotic factors in a tundra
abiotic factors in a prairie
abiotic factors in an ocean
Strep throat is a common human illness often caused by the bacterium Streptococcus pyogenes. Which term best classifies the colonies of Streptococcus pyogenes in a person with strep throat?
a population
an organelle
a community
an ecosystem
A student studying the biosphere makes a list of biotic and abiotic characteristics of various biomes. Which characteristic is considered a biotic factor?
dry, sandy, nutrient-poor soil in a desert
less than 25 cm of precipitation in a desert
evergreen trees present in a coniferous forest
temperature range of -40 to 40°C in a grassland
Which example describes a mutualistic relationship between organisms?
Young wasps prey on caterpillars.
Crabs eat the remains of dead fish.
Ants protect a tree on which they feed.
Tapeworms feed on food in the intestines of cats.
Most of the water on Earth is located in the oceans and has a salinity of about 3.5%. Which statement best explains why rain is fresh water and has a very low salinity?
When water precipitates from oceans, most of the salt remains in the oceans.
When water evaporates from oceans, most of the salt remains in the oceans.
When water precipitates from clouds, most of the salt remains in the clouds.
When water evaporates from clouds, most of the salt remains in the clouds.
Why are nonnative species often considered a disturbance in an ecosystem?
They increase mutations.
They compete for resources.
They have special growth needs.
They cause increased biodiversity.
A student listed characteristics of a classroom aquarium ecosystem. Which characteristic is a biotic component of the aquarium ecosystem?
The water temperature is 23°C.
The pH of the water is usually between 6.5 and 6.8.
The ammonia is controlled with a filter that uses two types of bacteria.
The lighting is supplied by natural sunlight and a fluorescent light bulb.
Tadpoles grown in ponds with high densities of tadpoles have lower survival and growth rates than tadpoles grown in ponds with lower densities of tadpoles. Which interaction between tadpoles grown in high-tadpole-density ponds would most likely cause the decreased survival and growth rates?
symbiosis
mutualism
competition
commensalism
Which population description is most likely represented by the graph?
A population of birds quickly increases but then becomes stable due to limiting factors in the environment.
A population of mice slowly increases but then fluctuates seasonally as predators raise their young and limit prey populations.
A population of fish quickly increases in the spring when there is plenty of food but then decreases quickly in the fall when food is limited.
A population of wolves slowly increases because of limiting factors in the environment but then increases constantly when additional prey migrate into the environment.
Step 1 - Analyze the water for the presence of different pesticides.
Step 2 - Communicate the data and results of the investigation to a peer-reviewed scientific journal.
Step 3 - Draw a conclusion about any pesticides found in the water that could be causing the extinction of water fleas.
Step 4 - Collect additional samples from Presque Isle Bay and the waters north and east of Presque Isle.
Which sequence of steps is needed for the scientist’s hypothesis about the absence of amphipods to eventually become a theory?
3, 2, 4, 1,
4, 3, 1, 2
1, 4, 2, 3
4, 3, 2, 1
Asian carp are an invasive species of fish. These large fish eat up to 40% of their body weight per day by feeding on phytoplankton. The carp also reproduce quickly. If these fish were to enter Lake Erie, how would the Presque Isle coastal ecosystem most likely be affected?
Producers in the ecosystem would grow at a faster rate, and smaller fish such as yellow perch would thrive.
The invasive fish would prey on mollusks such as mussels, but native fish species would quickly eat the invasive fish.
Consumers in the higher trophic levels would suffer stress, but crustaceans such as amphipods would be unaffected.
Most consumers in the ecosystem would face a shortage of food, and larger fish, such as walleye, would be unable to thrive.
