Item IE026004: Changes in a population may affect populations that are not directly connected by a feeding relationship even if they are several steps away in a food web (ocean ecosystem).

The diagram below shows the feeding relationships between populations of organisms in an area. The arrows point from the organisms being eaten to the organisms that eat them.

Using only the relationships between the organisms shown in the diagram, which of the populations of organisms would be affected if the seaweed were removed?

  1. Only the populations of large fish, seals, and killer whales would be affected.
  2. The populations of all of the organisms except the killer whales would be affected.
  3. Only the populations of shrimp, large fish, and small fish would be affected.
  4. The populations of all of the organisms would be affected.

Distribution of Responses

Chart showing distrubtion of responses for Item IE026004

Percent of students responding correctly

Overall73%
Grades 6–869%
Grades 9–1277%
Male70%
Female75%
Primary Language is English74%
Primary Language is not English58%

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