Module 2

• Levels of organization in living things

  Atom<|>Molecules<|>Organelle<|>Cell<|>Tissue<|>Organ<|>Organ system<|>Organism<|>Population<|>Community<|>Ecosystem<|>Biosphere
• Atom


  • Smallest scale, fundamental unit of matter
• Molecules


  • Chemical structure consisting of at least two atoms held together by one or more chemical bonds, DNA contains instructions for structure and functioning of body
• Organelle


  • Subunit of a cell, consist of functioning biomolecules, take part in chemical reactions and interactions of cellular processes
• Cell


  • Building blocks of life
• Robert Hooke discovered the cell by looking at a thinly cut piece of cork (dead cell walls of plant cell) through a primitive microscope
• Anton van Leeuwenhoek was the first to witness a live cell under a microscope in 1674, he is known as the Father of Microbiology
• Tissue


  • Group of similar cells performing specific function within an organism
• Organ


  • Collection of tissues grouped together performing a common function, vital organs in animals and plants
• Organ system


  • Higher level of organization that consist of functionally related organs
• Organism


  • Living individual entities which composed of various organ systems that function altogether
• Population


  • Group of organisms of the same species living together within a specific area
• Community


  • Group of organisms composed of different species which interact in a certain area
• Ecosystem


  • Group of organisms having an interaction with non-living environment (air, nitrogen, soil, rainwater)
• Biosphere


  • Global sum of all ecosystems and represents the zone of life on earth