Biology
The smallest chemical
unit of a type of pure
substance (element).
Example: Carbon atom
Atom
A group of joined atoms.
Example: DNA
Molecules
A membrane-bounded
structure that has a specific
function within a cell.
Example: Chloroplast
organelle
The fundamental
unit of life.
Example: Leaf cell
Cell
A collection of specialized
cells that function in a
coordinated fashion.
Example: Epidermis of leaf
Tissue
ORGAN
A structure consisting
of tissues organized to
interact and carry out
specific functions.
Example: Leaf
ORGAN SYSTEM
Organs connected physically or chemically
that function together. Example:
Aboveground part of a plant
ORGANISM
A single living individual.
Example: One acacia tree
POPULATION
A group of the same species of organism
living in the same place and time.
Example: Multiple acacia trees
COMMUNITY
All populations that occupy
the same region.
Example: All populations
in a savanna
ECOSYSTEM
The living and nonliving
components of an area.
Example: The savanna
BIOSPHERE
The global ecosystem;
the parts of the planet
and its atmosphere
where life is possible
Order
Atom, Molecule, organelle, cell, tissue, organ, organ system, organism, population, community, ecosystem, biosphere.
taxonomic rank greatest to smallest
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species (DKPCOFGS)