Download Levels of Organization

Unit 1 notes: Levels of Organization
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LIVING THINGS ARE ORGANIZED
 All living things show an orderly structure, or organization.
 In unicellular & multicellular organisms, all structures & functions of the organism form an
orderly living system.
Periodic table: Shows information about the known types of elements. Molecules & compounds can be
made by combining elements (atoms).
ORGANIZATION LEVELS (smallest to largest)
Atom: The basic & smallest unit of all matter (living & non-living).
Molecule: A combination of 2 or more atoms.
Organelle: A “little organ” composed of combined molecules that perform a specific job in a cell.
Cell: Formed from organelles. The basic unit of all living organisms. All organisms are composed of
cells.
Tissue: A group of cells working together to do 1 job.
Organ: A group of tissues working together to do 1 job.
Organ system: A group of organs working together to do 1 job.
Organism: A complete living thing. Can be a single cell or made of trillions of cells.
 Unicellular: made of 1 cell
 Multicellular: made of many cells
Population: A group of a single species in a specific location.
Community: Made of interacting populations that live in the same area.
Ecosystem: all the interacting biotic & abiotic factors in an area.
Biome: A group of ecosystems that share a similar climate and communities.
Biosphere: The thin portion around earth that supports life.
 Extends several kilometers above the earth’s surface up into the atmosphere.
 Extends several kilometers into the oceans down to the sea floor.
 Includes all biomes in the planet and ALL biotic & abiotic factors.
 The largest level of organization
 Biotic factors: all the living organisms that inhabit an environment.
 Abiotic factors: all the nonliving parts of an environment.
 air
 temperature
 moisture
 light
 soil
 Habitat: The area where an organism lives
 Niche: The role a species plays in a community
 Includes the space, food, and other conditions an organism needs to survive and reproduce.
 Includes how a species uses and affects its environment.