Biology 9 - Food Webs

What is the source of all energy in most ecosystems?

Primary producers

What do we call organisms that make their own food using sunlight?

Autotrophs or producers

Give two examples of producers in an ecosystem.

Wheatgrass and aspen trees

What is a primary consumer?

An organism that eats (primary) producers such as plants

Give two examples of primary consumers in an ecosystem.

Pronghorn, beavers, and elk

What is a secondary consumer?

An organism that eats primary consumers

What do we call animals that eat only other animals?

Carnivores

What do we call animals that eat only plants?

Herbivores

What is a decomposer? Give one example.

Bacteria

What is the role of decomposers in the flow of energy?

They release dead animals’ nutrients back into the environment, creating the cycle

Why do food chains usually have only 4–5 trophic levels?

Each trophic level, more energy is lost until (usually by 4 or 5) there is nothing left

What would happen if all the producers in an ecosystem died?

Everything else would die

What might happen if a predator is removed from an ecosystem?

There would be an overgrowth of primary consumers who would eventually run out of food due to overcrowding. Loss of biodiversity.

How does sunlight help start the flow of energy in an ecosystem?

It gives primary producers the energy to live

In a food web, what happens if one organism is removed or greatly reduced?

It disrupts population. The thing it preys on would grow, and its numbers will likely dwindle even lower.

How are food chains and food webs different?

Food chains show the linear transfer of energy—food webs are more in-depth and show the relationships between different animals.

Why is it important to have a balance between producers, consumers, and decomposers in an ecosystem?

Because too much of one will harm the rest of them.