C HAPTER 10 A LL CELLS COME FROM CELLS.

R EPRODUCTION Asexual reproduction-produces offspring that inherit all their genetic material from just one parent Example: Sea Stars and Plants

R EPRODUCTION CONTINUED …. Sexual reproduction- two parents are involved in the production of offspring. Examples: Egg and Sperm

R EPRODUCTION CONTINUED … Asexual and Sexual Reproduction-some unicellular and multicellular organisms Examples: Slime molds and Sea Anemones Can you think of some reasons why some organisms can do both?

R EPAIR AND G ROWTH Take a moment to look at the skin on your arm. Did you know that the outermost layer is actually dead cells? New cells are gradually moving toward the surface, replacing dead cells that have rubbed off. Asexual or Sexual reproduction? The replacement of lost or damaged cells is just one of the important roles cells reproduction plays in your life. Another is growth-simply increasing in size from a baby to a child to an adult.

T HE CELL CYCLE MULTIPLIES CELLS. Chromosomes and Cell Division 1. Chromatin -a combination of DNA and protein molecules 2. Chromosomes -when a cell divides, its chromatin fibers condense, becoming visible as they compact Human Body = Has how many chromosomes? Each chromosome may contain hundreds of genes

C HROMOSOMES AND C ELL D IVISION CONTINUED … Sister chromatids-two identical joined copies of chromosomes. Centromere-the region where the two chromatids are joined tightly together. *Draw Figure

C ELL C YCLE Cell Cycle -Eukaryotic cells that divide and undergo an orderly sequence of events. Interphase -the stage during which a cell carries out its metabolic processes and performs its functions. The cell may spend as much as 90 percent of the cell cycle in interphase.

C ELL C YCLE CONTINUED. Cell Cycle includes = Interphase and the M Phase (Mitosis) Interphase is divided into: 1. G 1 phase-cell grows 2. S phase-genetic material is duplicated 3. G 2 phase-cell prepares to divide 4. M phase (Mitosis) is divided into Prophase Metaphase Anaphase Telophase/Cytokinesis *Goes in order from 1 through 4.

D RAW F IGURE

M ITOTIC P HASE Mitotic phase -the stage of the cell cycle when the cell is actually dividing. Includes two processes: Mitosis and cytokinesis

M ITOTIC PHASE CONTINUED … Mitosis -the nucleus and the duplicated chromosomes divide and are evenly distributed forming two “daughter” nuclei. Unique to eukaryotes

M ITOTIC PHASE CONTINUED … Cytokinesis -process by which the cytoplasm is divided into two. Video