Slides in this set
Cells may appear inactive during this stage,
but they are quite the opposite. This is the
longest period of the complete cell cycle.
When a cell is not engaged in mitosis (which
is most of the time), it is said to be in
During this the nucleolus fades and
chromatins condense into chromosomes.
Each replicated chromosome comprises two
chromatids, both with the same genetic
The building blocks of microtubules are used
to grow the spindle from the region of the
The nuclear envelope breaks down
A protein structure, the kinetochore, appears at
the centromere of each chromatid.
With the breakdown of the nuclear envelope,
spindle fibers attach to the kinetochores as well as
to the arms of the chromosomes.
Then they line up in the equator.…read more
Spindle fibers shorten
The sister kinetochores suddenly separate and each
moves to its respective pole dragging its attached
chromatid (chromosome) behind it.
Separation of the sister chromatids depends on the
breakdown of the cohesin that has been holding them
together. It works like this. Cohesin breakdown is
caused by a protease called separase (also known as
Separase is kept inactive until late metaphase by an
inhibitory chaperone called securin.
Anaphase begins when the anaphase promoting
complex (APC)destroys securin (by tagging it for
deposit in a proteasome) thus ending its inhibition of
separase and allowing
separase to break down cohesin.…read more