MITOSIS

Asexual Reproduction  Reproduction with only one parent  offspring are identical to parents

Sexual Reproduction  Requires 2 parents  New individual is produced by the union of the nuclei of two specialized cells (sperm & egg)

Chromatin  Material that composes chromosomes

Histone  Proteins that DNA are wrapped around

Chromosomes  Structure in cells that undergo division and that contain hereditary information of the organism  In mitosis the chromosomes that undergo cellular division are called autosomes

CELL CYCLE  Cycle that a cell goes through in order to make new cells  If an organism is unicelluar, than a new organism is created via the cell cycle

Cell Cycle Consists of Two Parts:  Mitosis: –Division of the nucleus to form two identical nuclei –REMEMBER: Hereditary material is found in the nucleus  Cytokinesis –Division of the cytoplasm of the cell after mitosis

INTERPHASE

Interphase  Stage when a cell is between mitotic cycles: A. G1- cell grows B. S- DNA replication C. G2- Organelle replication

MITOSIS

Prophase  Chromosome become visible  Centrioles move to opposite poles of the cells  Microtubules form spindles  Spindle fibers become attached to centromeres  Nuclear membrane disappears  Nucleolus disappears

Prophase:

Metaphase  Chromosomes attach to the microtubule spindles  Chromosomes line up on the equator of the cell

Anaphase  Centromeres double  Chromosomes(si ster chromatids) move to opposite poles  Division (cleavage furrow) appears

Telophase  Begins when chromosomes reach the poles  Chromosomes uncoil and become invisible  Spindle disappears  Nuclear membrane forms  Nucleoli reappear

Telophase

Cytokinesis in Animal Cells  Begins during late anaphase  Cytoplasm is pinched off by cell membrane

Mitosis & Cytokinesis in Plant Cells  Main events are the same  Plants do not have centrioles or asters  Cytokinesis cannot occur by pinching off of membrane. A cell plate forms between the new cells during anaphase or telophase

Cytokinesis End with two identical daughter cells

Cells that divide rapidly  Plants  Animals

Cells that seldom or never divide  Xylem (part of a plant)  Nerve Cells  Muscle Cells