Transcript Cell Division - Mediapolis Community School

Cell Division
Mitosis and Cytokinesis
Cell Reproduction
• Interphase
– Cell growth, DNA synthesis, Growth and
Preparation
• Mitosis (Division)
– dividing the nucleus into two daughter nuclei
• Cytokinesis (Division)
– separating the organelles and the cytoplasm
Mitosis
• Mitosis is a continuous process that can be
observed in four stages:
– Prophase
– Metaphase
– Anaphase
– Telophase
Prophase 1
• Chromosomes begin to condense
• The nuclear membrane breaks down.
• Spindle which is made up of several spindle
fibers form.
– run at a right angle to the cell’s equator.
• An organelle called the centrosome helps
assemble the spindle.
– animal cells includes a pair of centrioles
– centrosomes move to opposite poles of the cell
Metaphase
• Chromosomes are packaged into their most
condensed form.
• Nuclear membrane is fully dissolved
• Chromosomes move to the center of the cell
• Spindle fibers form a link between the poles
and the centromere of each chromosome.
Anaphase
• Spindle fibers shorten
• Sister chromatids move toward opposite poles
as the spindle fibers shorten.
• Each pole now has a full set of chromosomes.
Telophase
• A nuclear envelope forms around the
chromosomes at each pole of the cell.
• Chromosomes now uncoil.
• The spindle dissolves.
• Mitosis is complete.
Cytokinesis
• The cytoplasm is separated
• Two daughter cells are formed
– Have half of the parent’s cytoplasm and organelles
– Genetically identical diploid cells
• After cytokinesis, each cell enters the G1 stage
of interphase.
•
Summary
The life of a eukaryotic cell cycles through;
– Growth, DNA replication
– preparation for cell division
– division of the nucleus and cytoplasm
• Mitosis is a continuous process that includes four stages:
–
–
–
–
Prophase
Metaphase
Anaphase
Telophase
• Cytokinesis
– the cell membrane grows into the center of the cell and divides
it into two daughter cells
– each daughter cell has about half of the parent’s cytoplasm and
organelles