WorksheetsFood Webs and Trophic Cascades
Total questions: 25
Worksheet time: 25mins
An interconnected web that represents the flow of energy (and what eats what) through an ecosystem, is referred to as a?
trophic level
trophic cascade
food web
food chain
Which of the following describes the broader consequences or side-effects when a certain species that usually helps to keep the entire ecosystem balanced is reduced or removed.
trophic level
trophic cascade
food web
keystone species
A (a) is casused by an animal at the top of the food chain and it affects every other organism. When an (b) is removed from a food chain it upsets the (c) of the whole ecosystem.
trophic cascade
apex predator
balance
What is a tropic cascade?
an ecological process triggered by the removal or addition of a top predator that causes changes throughout the food chain.
an ecological process triggered by the removal or addition of a top predator that causes no changes throughout the food chain.
an ecological process triggered by the removal or addition of a vegetation that causes no changes throughout the food chain.
an ecological process triggered by the removal or addition of a primary consumer that causes changes throughout the food chain.
Trophic cascades refer to...
impacts that reach beyond adjacent trophic levels.
impacts that reach the adjacent trophic level.
impacts that reach only one trophic level.
impacts that reach the top trophic level
How do the predators have a positive impact on the vegetation?
Since the predators eat the herbivores they eat the producers
Since the predators eat the herbivores and keep that population in check so they do not over eat the vegetation
The predators do not eat the vegetation so it is a positive impact
The predators eat the vegetation keeping it in control
A keystone species that is a critical food source for predator populations and increases the diversity of predators in an environment. For example, krill. This is referred to as a?
keystone predator
keystone prey
keystone ecosystem engineer
keystone plant
A keystone species that keeps populations under control by hunting consumers in the environment that may otherwise over populate and reduce diversity, is referred to as a?
keystone predator
keystone prey
keystone ecosystem engineer
keystone plant
African elephants eat A LOT of small trees and shrubs that would otherwise become forests. This allows open spaces that grow grassess for antelopes and zebras and provides warm soil for small rodents for burrowing. Elephants also spread seeds via their dung. They can therefore be described as?
Keystone predator
Keystone prey
Keystone producers
Keystone ecosystem engineer
Match the following trophic levels:
Producer
Plant
Primary consumer
Herbivore
Secondary consumer
Carnivore
Decomposer
Fungi
In the temperate forest, there are many (a) including trees, grass, and shrubs. These are eaten by (b) such as mice, rabbits and insects. (c) , such as snakes and foxes eat those. The (d) are animals like foxes, owls, and coyotes.
producers
primary consumers
Secondary consumers
apex predators
What would happen to an ECOSYSTEM if a KEYSTONE SPECIES DISAPPEARED?
It would COLLAPSE or not be able to survive.
It would help SUSTAIN the ecosystem.
The FOOD WEB would stay the same.
MIGRATORY species would arrive and take over.
Human population growth has led to a reduction in the populations of predators throughout natural ecosystems across the united states. Scientists consider the loss of these predators to have a
positive effect, because an increase in their prey helps to maintain stability in the ecosystem
positive effect, because predators usually eliminate the species they prey on
negative effect, since predators have always made up a large portion of our food supply
negative effect, because predators have an important role in maintaining stable ecosystems
Based on the graph shown, how can you tell sea otters are a keystone species?
as the sea otter population decreases, biodiversity increases
as sea otter population increases, biodiversity increases
changes in the sea otter population have little effect on biodiversity
the sea otter population dereases due to the presence of urchins
Choose all organisms associated with this trophic cascade.
What occurs in a positive feedback loop in a food web?
Change in one part of the ecosystem has no effect on the original change
Change in one part of the ecosystem stabilizes the original change
Change in one part of the ecosystem amplifies the original change
Change in one part of the ecosystem decreases the original change
What can cause trophic cascades in ecosystems?
Only human-induced changes
Only natural changes
Both natural and human-induced changes
Only changes in primary producers
What happens to the rest of the food web when a species is added to or removed from a specific food web?
Adding or removing a species causes the food web to collapse
Adding or removing a species has no impact on the food web
The rest of the food web remains unaffected
The rest of the food web can be affected
What happens in a negative feedback loop when the population of herbivores increases in an ecosystem?
The herbivores population decreases
The herbivores population increases
The producer population increases
The producer population decreases
What is the main advantage of using food webs over food chains?
They provide a linear representation of energy transfer
They simplify the understanding of energy flow
They capture the complexity of trophic interactions
They emphasize the importance of producers
Which of the following best describes a food web?
A network of interconnected food chains in an ecosystem
A linear sequence of organisms where each is eaten by the next
A diagram showing only the producers in an ecosystem
A chart depicting the energy flow in a single food chain
What is a trophic cascade?
A series of changes in an ecosystem triggered by the addition or removal of a top predator
A process where primary producers increase due to more sunlight
A chain reaction caused by the extinction of a plant species
A gradual change in climate affecting all trophic levels
In a food web, what role do decomposers play?
They break down dead organisms, returning nutrients to the soil
They are primary producers that create energy from sunlight
They are top predators that control the population of herbivores
They are secondary consumers that eat primary consumers
How can the removal of a keystone species affect an ecosystem?
It can lead to a collapse of the ecosystem
It will have no effect on the ecosystem
It will increase biodiversity
It will only affect the top predators
Which of the following is an example of a real-world trophic cascade?
The reintroduction of wolves to Yellowstone National Park affecting the entire ecosystem
The increase in algae due to more sunlight in a pond
The extinction of a single plant species in a rainforest
The migration of birds during winter
