Keystone Species

What role do producers play in an ecosystem?

• They are organisms that create their own energy through photosynthesis or chemosynthesis and form the base of the food chain.

• They are organisms that consume primary consumers and are at the top of the food chain.

• They are organisms that decompose organic material and recycle nutrients back into the ecosystem.

• They are organisms that rely on other organisms for energy and cannot produce their own.

What is a food web?

• A simple chain of organisms that eat one another.

• A complex network of feeding relationships among various organisms in an ecosystem, showing how energy and nutrients circulate.

• A diagram that only shows the primary producers in an ecosystem.

• A list of all the animals in a specific habitat.

What is a keystone species?

• A species that has a minor effect on its environment

• A species that has a disproportionately large effect on its environment relative to its abundance

• A species that is the most abundant in an ecosystem

• A species that is always at the top of the food chain

How do keystone species maintain ecosystem balance?

• By controlling populations of other species, which affects the entire community.

• By increasing biodiversity and introducing new species.

• By eliminating predators to allow prey populations to thrive.

• By competing with other species for resources and space.

How do environmental changes affect keystone species?

• They have no effect on keystone species.

• They can lead to imbalances in the ecosystem by threatening keystone species.

• They only affect non-keystone species.

• They improve the conditions for keystone species.

What is the 10% rule in ecology?

• The 10% rule states that only about 10% of the energy from one trophic level is transferred to the next level in a food chain.

• The 10% rule states that 10% of species in an ecosystem are predators.

• The 10% rule indicates that 10% of the population can be harvested sustainably.

• The 10% rule suggests that only 10% of the energy is lost as heat in a food chain.

What is the difference between primary consumers and secondary consumers?

• Primary consumers are carnivores that eat primary consumers, while secondary consumers are herbivores that eat producers.

• Primary consumers are herbivores that eat producers, while secondary consumers are carnivores that eat primary consumers.

• Primary consumers are omnivores that eat both plants and animals, while secondary consumers are herbivores that eat plants.

• Primary consumers are animals that produce energy, while secondary consumers are plants that consume energy.

What is the significance of decomposers in an ecosystem?

• Decomposers break down dead organic matter, recycling nutrients back into the ecosystem and supporting plant growth.

• Decomposers primarily consume living plants and animals, preventing overpopulation.

• Decomposers are responsible for photosynthesis, converting sunlight into energy for plants.

• Decomposers create new organic matter from inorganic substances, enriching the soil.

What is a trophic level?

• A position in a food chain or food web, defined by how an organism obtains its energy.

• A measure of the energy efficiency of an ecosystem.

• A type of organism that can produce its own food.

• A level of biodiversity within an ecosystem.

What happens to energy as it moves up trophic levels?

• It increases due to accumulation of energy.

• It remains constant across all levels.

• It decreases due to energy loss through metabolic processes, heat, and waste.

• It is completely transferred to the next level.