The Cell Cycle & Cell Division (Eukaryotic cells)

Why do cells divide? a. To replace old or injured cells b. For growth and development c. For reproduction of species

Eukaryotic Cells have a Life Cycle Eukaryotic Cells have a Life Cycle The life cycle of a cell includes three main stages: 1. Interphase 2. Mitosis 3. Cytokinesis

Interphase – preparing for division Animal & Plant Cell  Cell increases in size  Conducts life processes  DNA replicates

Mitosis The process of cell division which results in the production of two daughter cells from a single parent cell. The daughter cells are identical to each other and the parent

Prophase - prepares for nuclear division Animal Cell ◦ Chromosomes - rod-like and visible ◦ Spindle fibers form ◦ Centrioles move to poles Plant cell ◦ Same activities as animal cell Except: ◦ No centrioles in plants

Prophase

Prophase Animal Cell Plant Cell Photographs from:

Metaphase – Nuclear Division Metaphase – Nuclear Division Animal Cell & Plant ◦ Chromosomes line up at the center of the cell and attach to spindle fibers at the centromere

Metaphase

Metaphase Animal Cell Plant Cell Photographs from:

Anaphase – Nuclear Division Anaphase – Nuclear Division Animal & Plant Cell ◦ Spindle fibers pull chromosomes apart ◦ ½ of each chromosome (called chromatid) moves to poles

Anaphase Animal Cell Plant Cell Photographs from:

Anaphase

Telophase – Nuclear Division Telophase – Nuclear Division Animal Cell ◦ Spindle fibers disappear ◦ 2 nuclei form ◦ Cell membrane begins to pinches in Plant Cell ◦ Same activities,EXCEPT: - Cytoplasm does not pinch in. ◦ Cell plate forms ◦ Cell plate becomes cell membrane and cell wall.

Telophase Animal Cell Plant Cell Photographs from:

Cytokinesis - Cell Division Animal Cell -Cytoplasm pinches in two. -Two new daughter cells with exact number and type of chromosomes as parent cell Plant Cell -Cell plate becomes cell membrane and cell wall.

Cytokinesis – Two daughter cells exactly like parent cell (The Cell Cycle starts again with Interphase)

BrainPop

Animal Mitosis

Plant Mitosis

Your Turn On page 32: ◦ Draw the cell cycle found on page 179. ◦ Draw and explain the stages of Mitosis