Question 1: Define a food web and explain how it differs from a food chain.

Answer: A food web is a network of interconnected food chains showing how multiple energy pathways exist in an ecosystem. Unlike a food chain, which shows a single pathway, a food web depicts the complex feeding relationships among various organisms.

Question 2: List three types of organisms commonly found at different levels of a typical food web.

Answer: Producers (e.g., plants), primary consumers (herbivores like rabbits), secondary consumers (carnivores like foxes).

Question 3: Explain the role of decomposers in a food web.

Answer: Decomposers break down dead organic material, recycling nutrients back into the soil, which supports producers and maintains ecosystem health.

Question 4: Calculate the total energy transfer if a producer receives 1000 units of energy and 10% is transferred to each subsequent consumer. How much energy does the secondary consumer receive?

Answer: Secondary consumer receives 10 units of energy.

Question 5: Which of the following best describes a primary consumer? A) An organism that makes its own food B) An organism that eats producers C) An organism that decomposes organic matter D) An organism that eats secondary consumers

Answer: B) An organism that eats producers

Question 6: Fill in the blank: In a food web, if a keystone species is removed, it can cause a significant disruption in the entire ecosystem because it influences many other _______________.

Answer: species

Question 7: Describe a practical experiment to demonstrate how energy decreases as it moves up trophic levels in a food web. Include the variables involved and safety precautions.

Answer: Students can measure biomass or caloric content at different trophic levels in a controlled environment, such as a terrarium. Independent variable: trophic level; dependent variable: biomass or energy content. Safety precautions include handling organisms ethically, avoiding contamination, and proper disposal of biological material.

Question 8: A scenario describes a small pond ecosystem: algae (producer), small fish (primary consumer), larger fish (secondary consumer), and decomposers. If the algae population decreases drastically, predict and explain the potential impact on the entire food web.

Answer: A decline in algae would reduce food availability for small fish, leading to a decrease in their population. This would subsequently affect larger fish that rely on small fish for food, potentially causing a collapse or imbalance in the ecosystem. Decomposers may increase due to more dead organic matter.

Question 9: Identify and explain two ways human activities can disrupt food webs in ecosystems.

Answer: Overfishing can remove key species, disrupting predator-prey relationships; pollution can kill or harm organisms, reducing biodiversity and altering food web dynamics.