Worksheets06 Communities and Ecosystem Dynamics Quizs
Total questions: 20
Worksheet time: 10mins
After a volcanic eruption creates a new island, the first organisms to establish populations would most likely be:
Lichens and mosses
Large mammals
Tall trees
Fish
A forest fire destroys most trees in an area but leaves the soil intact. The regrowth process that follows would be classified as:
Primary succession, because the area was completely destroyed
Secondary succession, because soil and some organisms remain
Climax community formation, because trees will grow back
Pioneer colonization, because new species will arrive
The concept of ecological niche differs from habitat because niche includes:
Only the physical location where an organism lives
The organism's role, interactions, and resource use in addition to location
Only the food sources available to an organism
Only the predators and competitors an organism faces
The competitive exclusion principle predicts that zebras, wildebeest, and gazelles can coexist in the same grassland because they:
Migrate at different times of the year
Have different predators hunting them
Feed on different parts of plants or at different heights
Reproduce at different rates
If climate change causes the temperature tolerance range of a mountain species to shift upward, the most likely outcome would be:
The species' habitat range expands to include more area
The species' habitat range contracts toward higher elevations
The species develops new temperature tolerances immediately
The species' population increases due to less competition
According to the tolerance concept, an organism experiencing environmental stress would most likely be found:
In the center of its optimal range where conditions are ideal
At the edges of its tolerance range where conditions are marginal
Only in areas with no environmental variation
In regions with the highest biodiversity
A scientist studying pond ecosystems discovers that dragonfly larvae with different leg structures occupy different areas of the same pond. This observation best supports which ecological concept?
Habitat destruction leads to species extinction
Microhabitats allow multiple species to coexist by reducing direct competition
Larger habitats always support more species than smaller ones
All species in an ecosystem compete for identical resources
If wolves were permanently removed from Yellowstone again today, which sequence of events would most likely occur over the next decade?
Elk populations decrease → vegetation increases → biodiversity increases
Elk populations increase → vegetation decreases → stream erosion increases
Bear populations increase → fish populations decrease → bird populations increase
Deer populations decrease → predator populations increase → plant diversity increases
In a kelp forest ecosystem, sea otters control sea urchin populations, which prevents overgrazing of kelp. If sea otters were removed, the most likely outcome would be:
Kelp forests expand because there are fewer predators
Sea urchin populations crash due to lack of protection
Kelp forests decline due to increased sea urchin grazing
Fish populations increase due to more available habitat
Termites are able to digest wood because of microbes that live in their gut. The relationship between a termite and the microbes inside it is an example of what type of symbiosis?
parasitism
mutualism
commensalism
a predator-prey relationship
An ecosystem with high genetic diversity within species, many different species, and multiple habitat types would be considered to have:
Low biodiversity because it's too complex to be stable
High biodiversity across all three levels of biological organization
Moderate biodiversity because diversity at one level limits others
Unstable biodiversity because there's too much competition
A disease kills 80% of the snowshoe hare population in a region. Based on predator-prey relationships, what would you predict for the lynx population over the next few years?
Lynx population will immediately increase due to less competition
Lynx population will decrease due to reduced food availability
Lynx population will remain stable because they can switch prey
Lynx population will increase then stabilize at a higher level
The reintroduction of wolves to Yellowstone caused changes that affected river patterns and vegetation growth throughout the ecosystem. This phenomenon is best described as:
A trophic cascade
Primary succession
Competitive exclusion
Symbiotic mutualism
Which sequence correctly represents the typical order of secondary succession after a forest fire?
Grasses → shrubs → fast-growing trees → mature forest
Mature forest → shrubs → grasses → bare soil
Fast-growing trees → grasses → shrubs → mature forest
Shrubs → mature forest → grasses → fast-growing trees
A rancher notices that after removing all coyotes from his property, the rabbit population initially increases but then crashes dramatically due to overgrazing. This scenario best demonstrates:
Primary succession
The importance of keystone species in maintaining ecosystem balance
Competitive exclusion principle
Mutualistic relationships
Five warbler species living in the same forest avoid competition by feeding at different heights and locations within trees. This strategy is called:
Habitat fragmentation
Resource partitioning
Trophic cascading
Ticks that transmit Lyme disease to humans represent which type of symbiotic relationship?
Mutualism, because both the tick and bacteria benefit
Commensalism, because the bacteria doesn't harm the tick
Parasitism, because the tick harms its host while benefiting itself
Competition, because the tick and bacteria compete for resources
Two bird species that eat similar insects can coexist in the same forest if they:
Migrate to different areas during breeding season
Hunt at different times of day or in different parts of trees
Evolve to become identical in their feeding behavior
Compete directly until one species is eliminated
Which characteristic would most likely indicate that a species is a keystone species in its ecosystem?
It is the most abundant organism in the community
Its removal causes disproportionately large changes in ecosystem structure
It occupies the largest physical space in the habitat
It has the longest lifespan of all species present
A small fish that cleans parasites from larger fish while gaining food for itself demonstrates:
Parasitism, because the small fish depends on the larger fish
Commensalism, because only the small fish benefits
Mutualism, because both species receive benefits
Competition, because both fish are seeking the same resources
