1. WHAT…..???????  REPAIRS BROKEN BONES, BURNS, CUTS, AND SCRAPES?  CAUSES CANCER?  TRANSFORMS US FROM 2 CELLS TO 20 BILLION?

4.  Allows organisms, including you, to GROW  Replace old cells  Increases the number of cells

5.  Every day billions of red blood cells in your body are destroyed and need to be replaced --- HOW? MITOSIS  During the time it takes to read this sentence, 6 million new red blood cells were produced!

6. Begins with organism’s formation or birth Growth and DevelopmentDeath Individual cells follow the same life cycle

7.  Cell Cycle: series of events that takes place from one cell division to the next  Not the same for all cells  Examples ▪ Bean Plants 19hours ▪ Animal Embryos 20 min

9. 1. INTERPHASE 2. MITOSIS 1. PROPHASE 2. METAPHASE 3. ANAPHASE 4. TELOPHASE

10.  Period of growth &development  Before a cell can divide, a copy of its hereditary material must be made  So each new cell can receive a copy  Nucleus divides & cytoplasm separates

11.  Mitosis: nucleus divides to form two identical nuclei  Steps 1. Prophase 2. Metaphse 3. Anaphase 4. Telophase

12.  A Chromosome is a structure that contains the cell’s hereditary material (DNA)  Found inside the nucleus

13.  When cells are ready to divide, each duplicated chromosome condenses into thick strands called chromatids  Chromatids: duplicated chromosomes formed during interphase that are thick and coiled together  Needed for mitosis

15. Centromere

17.  Chromatids are tightly coiled together  Nucleolus and nuclear membrane disintegrate  Spindle fibers begin to stretch across the cell

19.  The chromatid pairs line up along the equator (or middle) of the cell

20.  Pairs of chromosomes are separated  Each half of the chromatid is pulled to an opposite side of the cell

21.  Spindles disappear  Chromosomes uncoil  New nucleus forms  Mitosis ends

22.  After mitosis  Cytoplasm separates  Cell membrane moves inward and pinches off  = TWO separate cells Cytokinesis

23.  Division of the nucleus  Produces two new nuclei that are identical to each other and the original cell  Each cell in your body has 46 chromosomes or 23 pairs  Each new cell also has 46 chromosomes

25.  Sexual reproduction requires two organisms  Asexual reproduction: a new organism is produced from one parent  Produces offspring that are identical to parent

26.  Reproduce asexually  Produce horizontal stems called runners that create new strawberries

27.  Bacteria CANNOT reproduce by mitosis  They are prokaryotic –  NO Nucleus  Reproduce by fission  Used by cells with no nucleus to copy genetic information and divide

28.  New organism grows from the body of the parent  When the bud is large enough it breaks away to live on its own

29.  Some organisms can regrow damaged or lost body parts  Sea Stars

30.  Cancer is the result of errors during mitosis  Normally healthy cells being reproducing out of control and can grow into structures called tumors