Question 1: Define food security in the context of ecology.

Answer: Food security refers to the availability and access to sufficient, safe, and nutritious food to meet dietary needs and preferences for an active and healthy life.

Question 2: Explain how energy flows through trophic levels in an ecosystem.

Answer: Energy flows from producers to consumers through feeding relationships, with energy being transferred at each trophic level, but most is lost as heat due to metabolic processes, resulting in less energy available for higher levels.

Question 1: Calculate the energy transferred from a trophic level if a primary producer biomass of 10,000 kg contains 4,000,000 kJ of energy, and a primary consumer biomass of 2,000 kg contains 800,000 kJ of energy. Use the formula: Energy transfer (%) = (Energy at higher trophic level / Energy at lower trophic level) × 100.

Answer: Energy transfer = (800,000 / 4,000,000) × 100 = 20%

Question 2: An agricultural process captures 1500 kg of wheat biomass containing 6,000,000 kJ of energy. If only 10% of this energy is transferred to livestock feeding on this wheat, how much energy is transferred?

Answer: Energy transferred = 10% of 6,000,000 kJ = 600,000 kJ

Question 1: Outline the key variables that need to be controlled and measured in an experiment assessing biomass transfer between trophic levels.

Answer: Variables include the type and amount of organisms, environmental conditions (light, temperature, humidity), and measurement techniques for biomass. Controlled variables are environmental factors to ensure consistent conditions.

Question 2: List safety precautions that should be observed when collecting biological samples in the field.

Answer: Wear appropriate clothing and gloves, handle specimens carefully to avoid injury, use tools safely, and follow local regulations and guidelines for wildlife and habitat protection.

Question 1: In a pond ecosystem, primary producers contain 5,000 kJ of energy, herbivores contain 1,000 kJ, and carnivores contain 200 kJ. Explain what these data suggest about energy transfer efficiency across trophic levels.

Answer: The data suggest that energy transfer is inefficient, with only 20% from producers to herbivores and 20% from herbivores to carnivores, indicating significant energy loss at each trophic level.

Question 1: Describe two ways in which food security can be affected by changes in trophic levels within an ecosystem.

Answer: Food security can be affected by changes such as overfishing reducing top predators, which can cause trophic cascades and reduce biodiversity; and habitat destruction leading to loss of primary producers, thereby decreasing the energy available for higher trophic levels, ultimately impacting food availability for humans.

Question 1: Explain how sustainable farming practices can improve food security by influencing trophic levels in agricultural ecosystems.

Answer: Sustainable practices such as crop rotation, integrated pest management, and maintaining natural predator populations help preserve ecosystem balance, enhance productivity, and ensure consistent food supply, thereby improving food security.