IX. Ecology

• ecology is the study of environment and interactions between organisms
• biosphere is the layer of the earth that supports all life forms
• ecosystem refers to the environment where living and nonliving things exist and interact with each other
• biotic factors in ecosystem are the living factors. e.g. plants, animals
• abiotic factors in the ecosystem are the nonliving factors. e.g. sun, air, temperature
• producers are the primary sources of energy; can make their own food
• autotrophs are organisms that produce their own food
• consumers feed on other organisms in order to survive
• heterotrophs are organisms that obtain energy from other organisms
• herbivores are the primary consumers, particularly only eats plants
• carnivores are the secondary consumers; only consume meat
• omnivores are tertiary consumers; both consume plants and animals
• scavengers are animals that feed predominantly on dead plants and animals
• decomposers are organisms that hasten the decay and decomposition of animal matter
• ecological niche is the role performed by living things in the ecosystem
• habitat is the place where organisms stay
• food chain is the transfer of sun's energy from producers to consumers as organisms feed on one another
• food web is the overlapping food chains