Science Assessment ~ Topics ~ Interdependence in Ecosystems ~ Item IE026005 ~ Student Performance

The diagram below shows the feeding relationships between populations of organisms L, M, N, O, P, Q, R, and S 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 Ls were removed?

Only the populations of Os, Qs, and Ss would be affected.
The populations of all of the organisms except the Ss would be affected.
Only the populations of Ms, Os, and Ns would be affected.
The populations of all of the organisms would be affected.

Distribution of responses
Answer Choice		Overall	Grades		Gender		Primary Language
		n = 1482	6–8 n = 865	9–12 n = 615	Male n = 698	Female n = 767	English n = 1342	Other n = 104
A.	Only the populations of Os, Qs, and Ss would be affected.	7%	6%	7%	8%	6%	7%	8%
B.	The populations of all of the organisms except the Ss would be affected.	7%	8%	7%	9%	6%	7%	7%
C.	Only the populations of Ms, Os, and Ns would be affected.	13%	14%	12%	13%	13%	12%	19%
D.	The populations of all of the organisms would be affected.	73%	72%	74%	71%	75%	74%	66%

Science Assessment

Item IE026005: 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 (no specific organisms indicated).