Energy Flow in Ecosystems Quiz

Abigail and Oliver are studying food webs, which diagram the complex relationships of energy flow in an ecosystem containing a variety of producers and consumers. Which of the following correctly shows one path that energy would flow through an ecosystem?

• Grasshopper → termite → warthog → hare

• Star grass → ants → aardvark → hyena

• Red oat grass → termite → Star Grass

• Hyena → aardvark → antelope → harvester ant

Answer explanation

The correct path is Star grass → ants → aardvark → hyena, showing energy flow from a producer (Star grass) to primary consumers (ants), then to a secondary consumer (aardvark), and finally to a tertiary consumer (hyena).

In the arctic food chain "plankton → forage fish → seals → polar bear," what is the role of the polar bear in this ecosystem?

• Omnivore

• Parasite

• Herbivore

• Predator

Answer explanation

In the arctic food chain, the polar bear is a predator as it preys on seals, which are higher up in the food chain. This role is crucial for maintaining the balance of the ecosystem.

In a simple food chain where the grass is eaten by the grasshopper, which is eaten by the snake, which is eaten by the hawk, which of these would have the largest amount of available energy?

• Grasshopper

• Grass

• Snake

• Hawk

Answer explanation

In a food chain, energy decreases as it moves up trophic levels. Grass, being the primary producer, has the most available energy, while the hawk, at the top, has the least. Therefore, the grass has the largest amount of available energy.

Michael and Grace are studying a food web in their biology class. The food web includes grass, grasshopper, frog, snake, and hawk. If the snake population decreases, what might be a possible consequence in this ecosystem?

• Increase in frog population

• Decrease in grasshopper population

• Increase in hawk population

• Decrease in grass population

Answer explanation

If the snake population decreases, there will be fewer predators of frogs. This reduction in predation pressure can lead to an increase in the frog population, as more frogs survive and reproduce.

In a forest ecosystem, if the trees (primary producers) are removed, what is the most likely impact on the ecosystem?

• Increase in herbivores (primary consumers)

• Decrease in carnivores (secondary consumers)

• Increase in top predators (tertiary consumers)

• No impact on the ecosystem

Answer explanation

Removing primary producers disrupts the base of the food web, leading to a decrease in available food for primary consumers. Consequently, secondary consumers, which rely on primary consumers for food, will also decrease.

David and Harper are studying an ecosystem in their biology class. If a new predator is introduced into this ecosystem, which of the following is a potential effect on the existing food web?

• Increase in prey population

• Decrease in competing predators

• Increase in primary producers

• No change in the ecosystem

Answer explanation

Introducing a new predator can lead to a decrease in competing predators as they may be outcompeted or preyed upon. This can alter the dynamics of the food web, affecting prey populations and overall ecosystem balance.

In a forest ecosystem, what might happen if a disease significantly reduces the population of deer, which are primary consumers?

• Increase in wolves, which are secondary consumers

• Decrease in grass and shrubs, which are primary producers

• Increase in grass and shrubs, which are primary producers

• No effect on the ecosystem

Answer explanation

If a disease reduces the primary consumer population, there will be less grazing on primary producers. This allows primary producers to thrive and increase in number, as they face less competition for resources.

When Aria introduced a non-native plant species into her garden, how might it affect the energy flow in the existing food web?

• It could increase the energy available to all trophic levels.

• It could disrupt the balance, leading to a decrease in native species.

• It would have no effect on the energy flow.

• It would only affect the top predators.

Answer explanation

The introduction of a non-native species can disrupt the existing food web balance, often leading to a decline in native species as they compete for resources, ultimately affecting energy flow across all trophic levels.

In a forest ecosystem, if the population of wolves decreases, what is a possible effect on the ecosystem?

• Increase in deer population

• Decrease in fox population

• Increase in fox population

• Decrease in plant growth

Answer explanation

When a top predator's population decreases, secondary consumers may increase due to reduced predation pressure. This can lead to higher competition for resources among primary consumers, potentially increasing their numbers.

James and Mia are studying a forest ecosystem. What is the potential impact on the food web if a keystone species, like the gray wolf, is removed?

• The ecosystem will remain stable.

• There will be a significant change in the ecosystem structure.

• Only the keystone species will be affected.

• Primary producers will increase.

Answer explanation

Removing a keystone species disrupts the balance of the ecosystem, leading to significant changes in the structure. This can cause population declines or increases in other species, ultimately altering the food web.