Transcript What occurs during the M phase?

+
What occurs during the M
phase?
Sections 8.6 and 8.7
+
Mitosis and Cytokinesis
+
Prophase (including prometaphase)

Nuclear membrane breaks
down

Chromatin condenses into
chromosomes

Spindle fibers appear

Centriole + spindle fibers =
centrosome

Centrosomes move to poles

Nucleolus disappears

Kinetochore of centromere on
each sister chromatid attaches to
spindle fiber
+
Prophase…
+
Metaphase

Spindle is fully formed

Chromosomes line up in the
“middle” of the cell (at the
metaphase plate – which is
between the poles of the cell)
+
Anaphase

Nonkinetochore microtubules
elongate the cell

Centromeres of sister chromatids
split

Motor proteins of kinetochores pull
daughter chromosomes to the
poles centromere 1st along
microtubules

Ends when chromosomes reach
the poles
+
Telophase

Nuclear membranes reappear
(one around each set of
chromosomes)

Chromosomes uncoil to
chromatin

Nucleolus reappears

Spindle breaks down

Cytokinesis begins during this
stage
+
Cytokinesis

Division of cytoplasms

Starts during telophase

Animal Cells – pinching
inward forms a cleavage
furrow

Plant cells – vesicles align
between the two nuclei;
vesicles fuse to form a cell
plate; cell plate grows outward