Understanding Mitosis and Meiosis

• There are two types of cell division:
  • Meiosis
  • Mitosis
• Meiosis is the division of sex cells, like female eggs and male sperm.
• Mitosis is the division of all other cells in the body.
• During mitosis, parent cells divide to produce two daughter cells.
• Cell division is important for tissue growth, repair, and replacement.
• It is important to have a basic understanding of the terminology and cell cycle phases.

Interphase

• G1 Phase: new organs are produced, protein levels increase, and centrioles begin to replicate.
• S Phase: DNA replication occurs and DNA is unwound by enzymes.
• G2 Phase: centriole replication completes and the cell prepares for division.
• Once interphase is complete, the mitotic phase begins.
• Mitosis involves the division of the nucleus and cytokinesis involves the division of the cytoplasm.
• The M phase has 4 phases.

Prophase

• During prophase, chromatin, DNA and protein tightly pack to form chromosomes.

Metaphase

• Spindle fibers attach to chromosomes, aligning them in the middle of the cell at the equatorial plate.

Anaphase

• Centromeres holding sister chromatids together separate.
• Chromatids are pulled by the spindle fibers towards the poles of the cell.
• Each sister chromatid becomes a chromosome with its own centromere.
• Cytokinesis begins.

Telophase

• A new nuclear envelope forms around the chromosome.
• The nucleolus reforms within the nucleus, and spindle fibers break up and disappear.
• Chromosomes uncoil to form chromatin, and cytokinesis continues until complete.
• Two new daughter cells form, completing the process of cell division.

Cytokinesis

• Final step in cell division.