Consider the following statements regarding ecological pyramids: 1. In a parasitic food chain, the pyramid of numbers is always upright, 2. Pyramids of biomass are always inverted in marine ecosystems. 3. Pyramids of energy are never inverted. Which of the statements given above is/are correct?

Statement 1 is incorrect. In a parasitic food chain, the pyramid of numbers is usually inverted because a single host organism supports a large number of parasites. Statement 2 is incorrect. While pyramids of biomass are often inverted in marine ecosystems (where phytoplankton have a lower biomass than zooplankton), this is not always the case, and in some marine environments, it can be upright. Statement 3 is correct. Pyramids of energy are always upright because energy is lost at each trophic level as heat, so the energy available at higher trophic levels is always less than at lower trophic levels.