Neco 2025 Biology Question 43

In a 1‑ha grassland the following data were recorded: - Grass (primary producer): average mass per shoot = \(0.5\ \text{g}\), number of shoots = 10 000. - Grasshopper (herbivore): average mass per individual = \(0.2\ \text{g}\), number of individuals = 500. - Frog (carnivore): average mass per individual = \(30\ \text{g}\), number of individuals = 20. Assume the energy content of dry matter is \(4\ \text{kcal g}^{-1}\) and that only \(10\%\) of the energy at one trophic level is transferred to the next. (a) Calculate the total energy (in kcal) available at the producer, primary consumer and secondary consumer levels. (b) If a drought reduces the total biomass of the grass by \(20\%\) while the transfer efficiency remains \(10\%\), estimate the new expected number of frogs, assuming each frog requires \(10\ \text{kcal}\) to survive. Round your answer to the nearest whole number.