Within
the nucleus, the DNA is organized along with proteins into chromosomes. Unless
the cell is in the process of dividing, its chromosomes are too stringy and
entangled to be identified as individual structures. Instead, they appear
as a mass
of stained material commonly referred to as chromatin. When the nucleus
is preparing to divide this chromatin condenses. When this happens, the
chromosomes become thick enough to
be seen as separate structures.