Levels of Organization The various levels of organization include atoms, molecules, cells, tissues, organs, organ systems, whole organisms, populations, communities, ecosystems, and the biosphere.

Molecular Level:Atoms (molecules) Atoms are the smallest unit of matter that have the chemical properties of a particular chemical element. Molecules the smallest particle of a substance that retains all the properties of the substance and is composed of one or more atoms

Organelles An organelle is a tiny cellular structure that performs specific functions within a cell like the nucleus, mitochondria, and ribosomes

Cells The cell is the basic unit of structure and function of a living thing. Cells are specialized by size and shape for the job they do.

Tissues Tissues are made of the same type of cells grouped together to do a specific job.

Organs Organs are made up of different tissues that work together to do a job. Example: a heart is an organ made of all four tissues.

Organ Systems An organ system is a group of organs working together. Example: Human organ systems include circulatory, reproductive, digestive, nervous, respiratory.

Organisms Sum of all cells, tissues, organs and organ systems makes an organism.

Talk with your partner Which levels of organization come together to create a heart?

Population Level A population is group of freely interacting and breeding individuals of the same species. For example, all the bull frogs in a pond can be considered a population of bullfrogs.

Community Level A community is all the populations of different species living and interacting together in a distinct area. (e.g: all the species in a pond)

Discuss with your group Discuss what order these should be placed in order of increasing complexity: community, population, organelle, cell

Ecosystems Ecosystems are distinguishable groups of species and the abiotic (non-living) components of the environment with which the living creatures interact. Examples of ecosystems include forests, prairies, deserts.

All the ecosystems around the world make up the biosphere.

Discuss with your group A teacher on campus went to visit a rainforest in South America over summer vacation. Discuss the levels of organization she encountered on her trip from smallest to largest.