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Lesson Worksheet: Factors That Affect Environmental Balance Science

In this worksheet, we will practice describing factors that affect environmental balance.


What would happen if an environment does not have any predators?

  • APrey would become stronger because there is no competition.
  • BPopulations of prey would decrease and there would be no competition for food.
  • CPopulations of prey would increase until there is not enough food for them.


Fill in the blanks: Saprophytic organisms, such as and , get most of their nutrition from decomposing organisms.

  • Afungi, bacteria
  • Btigers, lions
  • Csharks, whales


Why are saprophytic organisms important to environmental balance?

  • AThey recycle chemical elements in the ecosystem.
  • BThey stop predators from killing prey.
  • CThey help prey to get rid of their weakest members.


Fill in the blanks: kill and eat weaker or less healthy members of the prey population. This helps maintain the members of the prey population.

  • ASaprophytes, weaker
  • BPredators, weaker
  • CPredators, stronger
  • DSaprophytes, stronger


What group of organisms attacks, kills, and eats other organisms?

  • ASaprophytes
  • BHerbivores
  • CPredators
  • DDecomposers
  • EPrey


Which group of organisms feeds on dead matter and breaks it down?

  • AAutotrophs
  • BProducers
  • CConsumers
  • DSaprophytes


A prey population can be negatively affected by the lack of predators.

Consider the following statements:

The number of weak members .

The population size .

The competition for shelter .

The competition for food .

Which word fills in the blanks above?

  • AIncreases
  • BStays the same
  • CDecreases


Fill in the blanks: Saprophytism is important for environmental . Without it, the bodies of dead organisms would remain without and would not be recycled for use by other .

Put the words in the correct order to complete the paragraph.


Fill in the blank: As the number of predators increases, the number of preys .

  • Aincreases
  • Bdecreases
  • Cstays the same


On examining a sample of a dead organism’s body, what kind of organisms can you find?

  • APredators
  • BAutotrophs
  • CSaprophytic organisms
  • DPreys

This lesson includes 21 additional questions for subscribers.

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