Ecosystems Assessment

In the energy pyramid here, how much of the energy in the producers gets passed to the herbivores?

• 10%
• 20%
• 80%
• 90%

In an ecosystem, birds depend on insects to survive. If someone spreads pesticide to control the insect population, which of the following is most likely to happen?

• The bird population will increase.
• The bird population will decrease.
• The bird population will decrease, then increase. 
• The bird population will decrease, then increase. 

Different kinds of plants living in the same area must compete for water. Which kind of plant has the greatest chance of survival?

• the plant with the largest leaves
• a plant with a compact root system
• the plant with the largest root system
• a plant with needles instead of leaves

How do carnivores obtain energy?

• They eat plants.
• They eat animals.
• They eat animals and plants.
• They eat the food they make.

Look at the energy pyramid. Where is the greatest amount of energy?

• A
• B
• C
• D

All of the nonliving parts of an ecosystem

• biotic factors

• abiotic factors

• consumers

• decomposers

Which organism in the food chain is a producer?

• Mongoose

• Snake

• Caterpillar

• Leaf

Which organism in this food web provides the most energy?

• Fox

• Grass

• Hawk

• Rabbit

Why are decomposers important in an ecosystem?

• They make food for other organisms

• They return nutrients to the soil

• They make their own food

• They are prey for predators

What would happen to this food web if a disease killed a lot of foxes?

• There would be more rabbits, frogs, and mice

• The hawks would also die

• There would be less rabbits, frogs, and mice

• The number of thrushes would increase