question_answer 20)

  Pyramid of numbers is (a) Always upright                                                           (b) Always inverted (c) Either upright or inverted                                      (d) Neither upright nor inverted

Answer:

                  (c) Pyramid of number in ecosystems can be inverted or upright. In terrestrial ecosystem pyramids of number is upright. In case of successive decrease in members of trophic level like a big tree it is inverted whereas pyramid of energy is always upright. Whereas pyramid of biomass may also be upright or inverted. In none of the case always inverted pyramid or neither any pyramid may be of obtained thus other options wrong.