Study Notes
Feeding relationships describe how energy is transferred through ecosystems, starting from the sun and moving through various organisms.
- Producer — an organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesis. Example: Plants and algae are producers that use photosynthesis to create food.
- Consumer — an organism that gets its energy by feeding on other organisms. Example: Animals like lions and humans are consumers.
- Herbivore — an animal that gets its energy by eating plants. Example: Cows and rabbits are herbivores.
- Carnivore — an animal that gets its energy by eating other animals. Example: Tigers and hawks are carnivores.
- Decomposer — an organism that gets its energy from dead or waste organic matter. Example: Bacteria and fungi are decomposers.
- Ecosystem — a unit containing all of the organisms and their environment, interacting together, in a given area. Example: A lake with its fish, plants, and water.
- Trophic level — the position of an organism in a food chain or food web. Example: Producers are at the first trophic level.
- Food chain — a series of organisms through which energy is transferred in the form of food. Example: Grass → Rabbit → Fox.
- Food web — a network of interconnected food chains. Example: A food web showing grass, rabbits, foxes, and hawks.
Exam Tips
Key Definitions to Remember
- Producer: Organism that makes its own food using sunlight.
- Consumer: Organism that feeds on other organisms for energy.
- Decomposer: Organism that breaks down dead matter for energy.
Common Confusions
- Confusing food chains with food webs.
- Misunderstanding the difference between pyramids of numbers and pyramids of biomass.
Typical Exam Questions
- What is a producer? An organism that makes its own food using sunlight.
- How does energy flow in a food chain? Energy flows from producers to various levels of consumers.
- Why are food chains rarely more than 5 organisms long? Due to energy loss at each trophic level.
What Examiners Usually Test
- Understanding of energy transfer in ecosystems.
- Ability to interpret and draw food chains and food webs.
- Differences between pyramids of numbers and pyramids of biomass.