Question 1: Define a Pyramid of Biomass and explain its significance in representing energy transfer in an ecosystem.

Answer: A Pyramid of Biomass is a graphical representation showing the total dry mass of living organisms at each trophic level in an ecosystem. It illustrates how biomass decreases at higher levels, highlighting energy transfer efficiency.

Question 2: Describe the main difference between Pyramids of Biomass and Pyramids of Number.

Answer: Pyramids of Biomass display the total dry mass at each trophic level, while Pyramids of Number show the quantity of individual organisms at each level.

Question 1: A producer has a biomass of 500 kg per hectare. The primary consumer feeding on it has a biomass of 50 kg per hectare. Calculate the biomass transfer efficiency (%) from producer to primary consumer. (Formula: (Biomass of consumer / Biomass of producer) x 100)

Answer: 10%

Question 2: If a secondary consumer has a biomass of 5 kg per hectare, what is the percentage decrease in biomass from the primary consumer (50 kg) to the secondary consumer? Show your working.

Answer: ((50 - 5) / 50) x 100 = 90%

Question 1: Outline a simple method for measuring the biomass of a plant population in a local park. Include key variables you would control and safety precautions you should take.

Answer: To measure plant biomass, select a representative area and harvest all plants within it. Dry the plants at a consistent temperature (e.g., 60°C) for 48 hours and weigh them using a scale. Variables to control include sample size, drying time, and temperature. Safety precautions involve wearing gloves to handle plants, using appropriate tools, and ensuring proper disposal of plant material.

Question 2: List two limitations of using dry biomass as a measure of trophic level productivity.

Answer: It does not account for water content, which can vary; and it may not reflect actual energy transfer efficiency between levels.

Question 1: A study reports the following dry biomass measurements per hectare: Producers - 1000 kg, Primary consumers - 200 kg, Secondary consumers - 50 kg. Describe the trend observed and explain what it indicates about energy transfer efficiency.

Answer: Biomass decreases at each trophic level, with a 20% transfer from producer to primary consumer and 25% from primary to secondary. This indicates energy loss at each level, consistent with ecological principles.

Question 1: Explain how knowledge of Pyramids of Biomass can be used to improve sustainable fishing practices.

Answer: Understanding biomass at different trophic levels helps set sustainable catch limits, ensuring that fishing does not deplete key species and disrupt ecosystem balance.

Question 2: Describe a real-world scenario where Pyramids of Biomass could assist in managing invasive species.

Answer: By measuring the biomass of invasive species relative to native species, ecologists can assess their impact on local ecosystems. This information guides control measures to reduce invasive populations and restore ecological balance.