Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
An ecosystem is a community of living (biotic) organisms interacting with non-living (abiotic) components like soil, sunlight, and water ().
Producers, such as green plants, are the foundation of most ecosystems. They convert solar energy into chemical energy through photosynthesis using carbon dioxide () and water ().
Interdependency refers to how organisms depend on one another for survival. For example, animals breathe in oxygen () and exhale carbon dioxide (), which plants then use for photosynthesis.
Energy flows through an ecosystem in one direction: from the Sun Producers Consumers Decomposers.
The '10% Rule' suggests that in a food chain, only about of the energy at one trophic level is passed on to the next level, while the remaining is lost as heat or used for metabolic processes.
Decomposers (like bacteria and fungi) play a vital role by breaking down dead organic matter, recycling nutrients back into the soil for use by producers.
📐Formulae
💡Examples
Problem 1:
In a simple food chain: Grass Grasshopper Frog. If the Grass produces of energy, how much energy is approximately available to the Frog?
Solution:
Explanation:
According to the rule, the Grasshopper receives . The Frog, being the next level, receives .
Problem 2:
Explain the gas exchange between a fish and aquatic plants in a sealed aquarium.
Solution:
The fish releases and the plant releases .
Explanation:
Through cellular respiration, the fish consumes and produces . The aquatic plants use the for photosynthesis to produce glucose () and release back into the water, demonstrating interdependency.
Problem 3:
Identify the primary source of energy for the ecosystem shown in the formula: .
Solution:
Sunlight (Solar Energy)
Explanation:
Photosynthesis requires an external energy input to convert inorganic molecules ( and ) into organic energy-rich molecules (). This energy comes from the Sun.