1.Cells divide for the survival of the individual organism 2.Cells divide for the survival of the species (group of similar organisms) Why Divide? The cell theory states that: All cells come from other living cells. All cells come from other living cells.

Cells divide for the survival of the individual organism  Cell division is used for growth, development, maintenance, and repair of the organism. This is carried out by: Mitosis- division of body cells to make more of the same kind of cell. –The parent cell is the original cell inside the organism that will divide (i.e. a skin cell) –The daughter cells are the two identical cells created when the parent cell divides/replicates Also a form of asexual reproduction

BASIC GENETICS Each cell in the human body contains two sets of 23 chromosomes (contains DNA/genetic material) Mitosis identically replicates this information No genetic modifications! Each cell in the body therefore has the same/identical genetic material Reproductive cells only have one set of chromosomes which combine to make a new person with different genetic material to both parents This is NOT through mitosis!!

Each cell has 23 different chromosomes. They’re arranged in pairs since 1 chromosome of the pair comes from the mom, the other from the dad. This makes a total of 46 chromosomes. MM PP M = maternal (mom) P = paternal (dad) “Pa” PM

1. Chromosome: coiled DNA structures within the nucleus containing genetic information that is passed on from generation to generation 2. Sister Chromatid: one of two identical “sister” parts of a duplicated chromosome 3. Centromere (A): chromosome region that joins 2 sister chromatids TEM 36,000  Centromere Sister chromatids

Cell Division: Mitosis Mitosis – “division of the nucleus”. It is a synchronized set of events that will separate chromosomes, so that the two nuclei formed will be identical. It is the beginning of cellular division. (PMAT)- –Prophase, Metaphase, Anaphase, & Telophase Mitosis Animation Simple

Stages of Cell Division Interphase Mitosis Cytokinesis - Getting ready for cell division - Prophase - Metaphase - Anaphase - Telophase -Splitting cytoplasm after mitosis

-Cell growth - DNA Replicates (doubles the amount of genetic material) - Cell prepares for division

- Nuclear membrane breaks down - DNA coils to appear as chromosomes - Spindle fibers attach to chromosomes - Centrioles separate to opposite poles

-Centromere of each double stranded chromosomes attach to spindle fibers - Chromosomes line up in middle of cell

- Centromeres divide and then separate -Spindle fibers shorten pulling chromatids apart to opposite sides of cell

- Chromosomes uncoil -Nuclear membrane forms around each new set of chromosomes - Cytokinesis begins

Cytokinesis 1.Cytokinesis is division of the cytoplasm 2.Distributes the organelles a.In animal cells, the cell membrane pinches in two. b.In plant cells, a cell plate forms across the middle.

What Phase Of the Cell Cycle Is It? ABC D EF Anaphase Interphase CytokinesisTelophase ProphaseMetaphase

Figure 12.0 Mitosis

Figure 12.4 The cell cycle

Uses of mitosis: Asexual Reproductions Growth Repair

Difference Between Plant and Animal Mitosis Animals have centrioles, Plants cells usually do not Animal cells divide by pinching in (Cleavage), Plant cells divide by forming a cell plate.

Cleavage furrow SEM 140  Daughter cells Cleavage furrowContracting ring of microfilaments TEM 7,500  Cell plate forming Wall of parent cell Daughter nucleus Cell wall New cell wall Vesicles containing cell wall material Cell plate Daughter cells

CANCER is the caused by uncontrolled cellular division. Typically, most cells don’t divide unless it is for repair or maintenance. Cancerous cells keep dividing; crowding out and stealing nutrients from healthy tissue. Cancer “kills” when a mass of cancer cells called a tumor interferes with the functions of major organs.

Tumor Glandular tissue A tumor grows from a single cancer cell. Cancer cells invade neighboring tissue. Cancer cells spread through lymph and blood vessels to other parts of the body. Lymph vessels Blood vessel Breast Cancer (uncontrolled cell growth)

Cells divide for the survival of the species 

- MITOTIC CELL DIVISION - One parent -Offspring genetically identical to parent cell -will have same #chromosomes parent cell -will have all same characteristics as parent cell - cytoplasm and organelles split equally Example: amoeba, paramecium, bacteria -single circular chromosome replicates before division

Unicellular:Uneven division of cytoplasm and organelles (ex. Yeast) Multicellular:-A cell of a parent develops a multicellular bud - eventually bud separates becoming separate organism (ex. Hydra)

-Mitosis with in specialized cells producing spores. -spore is DNA surrounded by a tough coat (survive harsh environment) - each spore can develop into a new organism Example: Bread Mold

- Replacement of lost or damaged body parts -Invertebrates show greater regenerative capacity than vertebrates - examples: lobster, starfish, planaria In some cases part can grow a new organism

New plant develops from part of a parent plant Bulbs:-Ex. Onion, Tulip Tubers: -Ex. Potato

Runners: -stem above the ground -new plants form where runners touches ground (Ex. Strawberries, spider plant) Rhizomes: -woody underground stem -swollen regions produce new plant (Ex. Poison Ivy, Ferns)

46 Single Chromosomes 46 Double Chromosomes 46 singles 46 singles Interphase PMATPMAT (Mitosis) Cytokinesis 2n 2n = diploid (normal chromosome # for species)

1. # nuclear divisions: 2. Chromosome # (identical or different from parent cell) 3. # daughter cells created 4. Genetic information (identical or different from parent) 5. Uses 6. When are chromosomes single, double? Everyone writes statement/answer in notebook Partner A answers: #1, Partner B answers: #2 etc. 1 Identical 2 Growth, repair, asexual reproduction Single=before interphase, after telophase Double= after interphase, until telophase

What are clones? - Genetically identical copies i.e. have the same traits

Hydra budding to make a clone

Amoeba dividing asexually, making a clone LM 340 

Bacteria dividing asexually These are CLONES as only have information from 1 parent

Strawberry plants making asexual clones Whole new plants grow at the end of the runners