Ecological Pyramids - Number, Biomass, Energy - Unsolved Practice Set

Q1. Ecological pyramids are graphical representations used to show:

1. The geographic distribution of species
2. The trophic structure and function of an ecosystem, in terms of number, biomass, or energy at each trophic level
3. The chemical composition of soil
4. The rate of photosynthesis alone

Q2. A pyramid of numbers that is inverted (narrow at the base, wide at the top) can occur in ecosystems such as:

1. A grassland with many grass plants supporting fewer herbivores
2. A single large tree supporting numerous insects, which in turn support fewer birds
3. A pond with countless phytoplankton supporting fewer zooplankton
4. Any typical forest ecosystem, without exception

Q3. In most terrestrial ecosystems, the pyramid of biomass is typically:

1. Inverted, with a small base and large top
2. Upright, with a large base of producer biomass narrowing toward higher trophic levels
3. Perfectly rectangular, with equal biomass at every level
4. Absent altogether

Q4. In certain aquatic ecosystems, the pyramid of biomass can appear inverted mainly because:

1. Producers (such as phytoplankton) have a small standing biomass but a very high turnover/reproduction rate
2. There are no producers in aquatic ecosystems
3. Energy flow is reversed in water
4. Consumers do not exist in aquatic ecosystems

Q5. The pyramid of energy in an ecosystem is:

1. Sometimes inverted, depending on the ecosystem
2. Always upright, since energy is progressively lost at each successive trophic level
3. Always absent in aquatic ecosystems
4. Unrelated to the concept of trophic levels