interphase
longest part of the cell cycle;
Chromosomes
copied
during DNA replication, appear as
threadlike
coils or chromatin
prophase
mitosis begins
; the nucleolus fades and chromatin condenses into chromosomes; the nuclear membrane breaks down so there is no longer a recognizable nucleus; spindle fibers form
metaphase
chromosomes line up in
middle
of cell
anaphase
chromatids separate
and are moved to opposite poles of the cell by the shortening spindle fibers
telophase
nuclear membranes form around the identical sets of chromosomes; the chromosomes uncoil; nucleoli appear in the two new nuclei; cytokinesis begins, splitting the cytoplasm and separating the two daughter cells
cytokinesis in animal cells
cell is pinched in two, creating two identical daughter cells
centromere
where
spindle fibers attach
during mitosis and meiosis
mitosis
cell division when nucleus divides into two nuclei containing the
same number
of chromosomes ending in
2 genetically identical cells
spindle fibers
special strands of microtubules which grow out of the centrioles, connect to chromosomes at the centromeres and pull them apart during mitosis
sister chromatids
two identical strands of the same chromosomes
centriole
where the microtubules of the spindle originate during mitosis in both plant and animal cells.
cytokinesis in plant cells
cell plate
grows outward until its membrane fuses with the cell membrane, separating the two daughter cells
G1 phase
the first gap or growth phase of the cell cycle; cell increases in size, organelles are replicated, cell carries out normal functions
Synthesis (S) phase
portion of interphase during which DNA is replicated
G2 phase
the second gap or growth phase of the cell cycle; occurs after DNA synthesis
G0 phase
Gap 0; a non-dividing state occupied by cells that have left the cell cycle, sometimes reversibly.
cell cycle
an ordered sequence of events in the life of a cell
checkpoints
points in the eukaryotic cell cycle that ensure the cell is ready to proceed before it moves on the to next phase of the cycle; occur in G1, S, and during metaphase
regulatory proteins
control the cell cycle by signaling the cell to either start or delay the next phase of the cycle
differentiation
the process by which a cell becomes specialized in order to perform a specific function
apoptosis
programmed cell death
tumor
disorganized clump of cancer cells that do not carry out the functions needed by the body
cancer
uncontrolled cell division of abnormal cells
growth factors
factors that stimulate the cell to divide
stem cell
an undifferentiated cell that has the ability to become a wide variety of specialized cells