Question 1: Define a Pyramid of Biomass and explain how it differs from a Pyramid of Energy.

Answer: A Pyramid of Biomass is a graphical representation showing the total biomass at each trophic level in an ecosystem. It differs from a Pyramid of Energy because it illustrates the amount of organic matter, whereas energy pyramids show energy transfer efficiency between levels.

Question 2: Describe the typical shape of a Pyramid of Biomass and explain why it usually appears that way in most ecosystems.

Answer: It typically has a pyramid shape, wider at the bottom and narrower at the top, because biomass decreases at higher trophic levels due to energy loss during transfers and less biomass can be supported at higher levels.

Question 1: If the biomass of producers in an ecosystem is 5000 kg per hectare, and herbivores have a biomass of 1000 kg per hectare, calculate the biomass transfer efficiency from producers to herbivores. Use the formula: (Biomass of herbivores / Biomass of producers) x 100%.

Answer: 20%

Question 2: A tertiary consumer has a biomass of 50 kg per hectare, while the secondary consumer has a biomass of 250 kg per hectare. Calculate the percentage decrease in biomass between these two levels.

Answer: 80%

Question 1: Describe a simple experiment to measure the biomass of plants in two different ecosystems. Include the variables you would control and safety precautions to consider.

Answer: Select similar plots in each ecosystem, harvest all plants, dry them to a constant weight, and weigh to determine biomass. Control variables include soil type, sunlight, and water availability. Safety precautions include wearing gloves, proper disposal of plant material, and avoiding disturbing wildlife.

Question 1: In an aquatic ecosystem, the biomass of phytoplankton is 2000 kg, herbivorous zooplankton is 500 kg, and small fish are 100 kg. Comment on the shape of the biomass pyramid and explain what this indicates about energy transfer in this ecosystem.

Answer: The pyramid shape shows a broad base with decreasing biomass at higher levels. This indicates efficient energy transfer from phytoplankton to zooplankton, but significant energy loss occurs as biomass decreases at each subsequent level.

Question 1: Explain the ecological significance of pyramids of biomass and how they help in understanding ecosystem health. (6 marks)

Answer: Pyramids of biomass provide insight into the amount of living organic matter at each trophic level, indicating the productivity and energy flow within an ecosystem. They help identify imbalances, overexploitation, or degradation, thereby serving as indicators of ecosystem health and sustainability.

Question 1: Discuss how knowledge of biomass pyramids can be used in managing fisheries and conserving aquatic ecosystems.

Answer: Biomass pyramids help determine sustainable harvesting levels, monitor ecosystem productivity, and identify overfishing or pollution impacts, aiding in effective management and conservation of aquatic resources.