Download Cell replication - Mitosis

Cell replication - Mitosis
12B
8th May 2012
Label diagrams
• Copy and label the diagrams on the board
Cell Replication Key facts
• Organism grows from a single celled zygote to an
adult organism by mitosis
• Each cell contains 46 chromosomes
• At the end of division we have two identical cells
• As cells get larger the surface area /volume ratio
decreases making diffusion less efficient. When
cells divide the surface area is increased which
enhances diffusion of nutrients and waste
excretion
• Mitosis cell division takes place all over the body
Cell cycle replication
Prophase
• Chromosomes can be seen as they start to
condense forming chromatids joined by
centromere
• Nuclear membrane starts to disappear
• Nucleolus start to disappear
• Centrioles migrate to each side of nucleus and
spindle starts to form
Metaphase
• Chromosomes line up along equator
• Each sister chromatid lined up on opposite
sides
• Chromatid joined to spindle by centromeres
Anaphase
• Chromatids separate
• Pulled to opposite poles by spindle
• Unattached spindles elongate
Telophase
• Mitosis complete
• Nuclear membrane forms
• Nucleoli reappear