Hierarchy of Biological Organization

Levels of Organization

Life is organizedLife is highly organized into

structural levels.Each level builds on the levels

below it.

AtomsChemical building blocks of

materOrganized into biological

molecules

OrganellesMolecules are

organized into small structures called organelles

Organelles are the components of cells

CellsSubunits of organisms.Cell is the smallest unit capable

of all life functionsSome organisms are only 1 cell. Ex. Amoeba

AMOEBA

Types of Blood cells

TissuesSimilar cells are grouped into

tissues.Nervous tissue, epithelial tissue,

muscle tissue, connective tissue

OrgansSpecific arrangement of different

tissue form organsHeart, lung, kidneyOrgans form organ systems like

the nervous system

Organ SystemsWhen organs work together they

form systems. Ex. Circulatory system

OrganismAll the other

parts form an organism that is part of a larger population.

Can continue to communities, ecosystems, and biosphere.

Beyond Individual OrganismThere are tiers beyond the

individual.◦Population: A group of species◦Community: Groups of populations of

species◦Ecosystem: Community interactions

that include non-living features.

Emergent PropertiesEach step upward in the

hierarchy of order, different properties emerge that were not present at the simpler level of organization.

Ex: Properties of proteins have attributes that were not exhibited by any of it’s component atoms.

Emergent Properties Cont.Emergent properties are integral

to the formation of life as non-living things are organized into what we perceive life to be.

This is what “life” resists a simple one-sentence definition.