From Wikipedia,
the free encyclopedia.
Multicellular organisms
are those
organisms containing more than
one
cell, and having
differentiated cells that perform
specialized functions. Most life
that can be seen with the naked
eye is multicellular; all
animals (i.e. members of the
kingdom Animalia) and
plants (i.e. members of the
kingdom Plantae) are.
Although some single-celled
organisms have differentiated
cells (e.g.
myxobacteria), the
differentiation is less dramatic
than that typically found in
multicellular organisms. A group
of similarly differentiated cells
performing a function in a
multicellular organism is known as
a
tissue.
Multicellular organisms must
solve the problem of regenerating
the whole from
germ cells (i.e.
sperm and
egg cells), an issue that is
studied in
developmental biology. The
overall spatial organization of
differentiated cells is a topic of
study in
anatomy. Multicellular
organisms can suffer from
cancer when cells fail to
regulate their growth within the
normal program of development.
See also
