Problem 1 - Biology: The Dynamic Science

Question

Which of the following events would move energy and material from a detrital food web into a grazing food web? a. A beetle eats the leaves of a living plant. b. An earthworm eats dead leaves on the forest floor. c. A robin catches and eats an earthworm. d. A crow eats a dead robin. e. A bacterium decomposes the feces of an earthworm.

Step-by-Step Solution

Answer

The correct answer is option c, A robin catches and eats an earthworm. The energy and nutrients that the earthworm originally extracted from dead organic material in the detrital food web gets passed to the robin, an organism in the grazing food web.

Step 1: Understand the Food Webs

In a detrital food web, decomposers break down dead organic material into simpler components, making nutrients available for plants or the producers of the grazing food web. An event that moves energy and material from the detrital food web to a grazing food web would usually involve an organism from the grazing food web consuming an organism from the detrital food web.

Step 2: Evaluate the Options

a. A beetle eating the leaves of a living plant transfers energy within the grazing food web, not from the detrital food web. b. An earthworm eating dead leaves transfers energy within the detrital food web, not to the grazing food web. c. A robin eating an earthworm moves energy from the detrital (the earthworm that consumes dead organic material) to the grazing food web. d. A crow eating a dead robin moves energy within the detrital food web, not to the grazing food web. e. A bacterium decomposing earthworm feces is a transfer within the detrital food web, not to the grazing food web.

Step 3: Identify the Correct Event

Therefore, the event that moves energy and material from a detrital food web to a grazing food web is when a robin catches and eats an earthworm (option c). The energy and nutrients that the earthworm originally extracted from dead organic material in the detrital food web gets passed to the robin, an organism in the grazing food web.