Biology · Ecosystems · NEET
The pyramid of biomass in the sea (and in a pond) is generally inverted. The producers are tiny phytoplankton with a very small standing crop (biomass). They are eaten by zooplankton and small fish, which are eaten by bigger fish. So the biomass increases as you go up, giving a narrow base and a wide top — an inverted pyramid. This is a very common NEET answer.
Because phytoplankton grow and reproduce extremely fast. At any single moment (the standing crop) only a small mass of phytoplankton is present, but they are being eaten and replaced constantly. So a small producer biomass can still feed a large biomass of consumers above it. The measured biomass at that instant looks inverted, even though the producers actually do most of the production over time.
No. The pyramid of energy is ALWAYS upright and can never be inverted. Energy is lost as heat at every trophic level (only about 10% passes up, the 10% law). So each higher level always has less energy than the level below it. NEET loves this: 'energy pyramid can never be inverted' is a correct statement.
Yes. In a single big tree ecosystem, one tree (producer) supports many fruit-eating birds and insects (primary consumers), which support even more parasites like lice and bugs. So the number increases upward and the pyramid of number becomes partly inverted. Note: this example is about NUMBER, not biomass.
No. In a forest the pyramid of biomass is upright. Large trees (producers) have a huge standing crop of wood and leaves at the base, and biomass decreases sharply going up to herbivores and carnivores. Only the AQUATIC (sea/pond) biomass pyramid is inverted, not the forest one.
Upright. In grassland, many small grass plants (producers) form a wide base, then fewer herbivores, then still fewer top carnivores. So numbers decrease upward and the pyramid is upright. Do not confuse this with the sea biomass pyramid, which is inverted.
Which of the following ecological pyramids is generally inverted?
What type of ecological pyramid would be obtained with the following data? Secondary consumer: 120 g; Primary consumer: 60 g; Primary producer: 10 g
Which of the following statements is not correct?
Try the real previous-year questions from this chapter — each with the answer and a full solution.
An ecological pyramid is inverted when a lower trophic level has less number or biomass than the level above it, making the base narrower than the top. This mainly happens with the pyramid of biomass in aquatic ecosystems (sea, pond) and the pyramid of number in a single-tree/parasite ecosystem.
The pyramid of energy is never inverted. It is always upright because energy is lost as heat at each trophic level, so every higher level has less energy than the one below it.
Phytoplankton reproduce very fast and are eaten as fast as they grow. So at any one moment (standing crop) their biomass is small, even though over time they produce enough food to support a large fish biomass. This makes the sea biomass pyramid inverted.
Yes. Like the sea, a pond is an aquatic ecosystem where small phytoplankton producers support larger consumer biomass, so its pyramid of biomass is also generally inverted.
Terrestrial ecosystems like forests and grasslands show upright pyramids of biomass, because large plant producers form a big biomass base that decreases going up the levels.
