In a forest where one large tree supports thousands of insects, which in turn feed a few birds, the pyramid of numbers is

spindle-shaped, narrow at the base and the top and wide in the middleCorrect answerYour answerupright, broad at the baseCorrect answerYour answera straight column of equal widthsCorrect answerYour answerimpossible to drawCorrect answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer A

Correct answer: A

Count the organisms at each level: one tree (narrow base), thousands of insects (wide middle), a few birds (narrow top).
So the pyramid of numbers bulges in the middle. The pyramid of energy, by contrast, is always upright.

Worth noting

Pyramids of numbers and biomass can take odd shapes; only the pyramid of energy can never be inverted.

Concept: Ecological pyramids
Typical timeTypical: 90 s
Your timeYours: —

The rule this testsFood chains and energy flow

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Ten questions from Ecosystems and Biodiversity, at your own pace.

In a forest where one large tree supports thousands of insects, which in turn feed a few birds, the pyramid of numbers is

Explanation