The_Cell_Cycle[1]

The Cell Cycle : 

The Cell Cycle BIOLOGY

Key Terms : 

Key Terms Genome—the total complement of an organism’s genes Chromatin—network of DNA and fibrils in a nucleus that is not dividing. Chromosome—structure of DNA that transmits genetic information to the next generation. Chromatids—two copies of the same chromosome attached together Centromere—constriction where sister chromatids of a chromosome are held together. Chromatin in a developing salamander ovum

Mitosis : 

Mitosis A diploid cell divides to produce diploid daughter cells. Diploid means that each cell has a pair of each chromsome (matched set) Ensures that each daughter cell contains the exact same chromosomes as the original mother cell. Mitosis maintains chromosome number.

Interphase : 

Interphase Most of the cell cycle is spent in interphase. G1 - all organelles double; gathers materials for DNA replication. S - DNA replication. G2 - Cell makes all the proteins necessary for cell division.

Prophase : 

Prophase Prophase Chromatin has condensed. Nucleolus disappears. Nuclear envelope disintegrates. Spindle begins to assemble.

Figure 12.5 The stages of mitotic cell division in an animal cell: G2 phase; prophase; : 

Figure 12.5 The stages of mitotic cell division in an animal cell: G2 phase; prophase;

Metaphase and Anaphase : 

Metaphase and Anaphase Metaphase Chromosomes, attached to spindle fibers, are lined up at the center of the cell. Anaphase Sister chromatids split, producing daughter chromosomes. Daughter chromosomes are pulled to opposite poles.

Telophase : 

Telophase Telophase spindle disappears new nuclear envelopes form around the daughter chromosomes. Chromosomes uncoil. Nucleolus appears in each daughter nucleus.

Cytokinesis : 

Cytokinesis Animal Cells: Cleavage furrow begins as anaphase finishes. Cytokinesis divides the cytoplasm and all organelles between the two new cells

Cytokinesis : 

Cytokinesis Plant Cells: Begins with formation of a cell plate which eventually becomes new plasma membrane between the daughter cells.

Figure 12.9 Mitosis in a plant cell : 

Figure 12.9 Mitosis in a plant cell

Figure 12-09x Mitosis in an onion root : 

Figure 12-09x Mitosis in an onion root