Problem 6 - Biology: The Dynamic Science

Question

Some freshwater and marine ecosystems exhibit an inverted pyramid of: a. biomass. b. energy. c. numbers. d. turnover. e. ecological efficiency.

Step-by-Step Solution

Answer

The correct answer is a. biomass.

Step 1: Understand the Concept of Ecological Pyramids

In the ecological system, the representation of the distribution of organisms, biomass, and energy in the form of a pyramid is called the ecological pyramid. There are primarily three types of ecological pyramids: pyramid of numbers, pyramid of biomass, and pyramid of energy.

Step 2: Distinguish Between Different Types of Ecological Pyramids

The pyramid of numbers refers to the number of organisms at each trophic level. The pyramid of energy represents the flow of energy from one trophic level to another. The pyramid of biomass refers to the total mass of organisms at each trophic level. Both pyramid of numbers and pyramid of energy are typically upright because energy decreases when it transfers from one trophic level to the higher one, while the number of organisms decreases due to predation. However, in some ecosystems, the biomass pyramid can be inverted. This is often seen in aquatic ecosystems, where the biomass of phytoplankton (which are at the bottom of the pyramid) is less than the combined biomass of zooplankton that feed on them.

Step 3: Identify the Correct Choice

Given the understanding of the various ecological pyramids and knowing that some ecosystems can exhibit an inverted pyramid of biomass, the correct answer becomes clear.