Mitosis & Asexual Reproduction Topic 15

Cell Theory Smallest unit of life Cells work together All cells come from pre-existing cells

Cell Division Make new cells Growth & repair All body cells EXCEPT sex cells Process: MITOSIS

Cancer Abnormal mitosis Uncontrolled cell division

DNA Deoxyribonucleic Acid Genetic code Instructions for building an organism

How DNA is Packaged- Dolan DNA Learning Center http://www.dnalc.org/resources/3d/07-how- dna-is-packaged-basic.html

Chromatin Uncoiled DNA Before mitosis – during interphase

Chromosome 2 copies of DNA – double stranded Shape- X

Chromatid & Centromere Chromatid- 1 side of chromosome Centromere- center, joins 2 chromatids together

Stages of Cell Division Interphase Prophase Metaphase Anaphase Telophase

Interphase Resting phase DNA is uncoiled- chromatin DNA replicates Cell grows

Prophase Chromosomes form Centrioles move to opposite poles Spindle fibers form Nuclear membrane disappears

Metaphase Centromeres line up in middle Spindle fibers attach to centromeres

Anaphase Sister chromatids move to opposite poles

Telophase At each pole chromosomes uncoil Nuclear membrane forms around each set

Cytokinesis Separates to make 2 daughter cells In animal cells: cleavage- cytoplasm pinches in and separates In plant cells: cell plate- forms new cell wall between 2 cells

Animal Plant

Difference Between Animal & Plant Cells Centrioles Cleavage PLANT No Centrioles Cell Plate

http://www.cellsalive.com/mitosis.htm http://www.youtube.com/watch?v=VlN7K 1-9QB0

Results of Mitosis 2 identical cells Same number of chromosomes Exact same DNA as parent cell

Asexual Reproduction Only one parent By the process of MITOSIS Let’s see which organisms reproduce this way….

Binary Fission Parent organism divides in 2 Equal division of cytoplasm Paramecium Ameba

E Coli bacteria growth http://www.youtube.com/watch?v=etTmg _7a814&NR=1

Budding Unequal division of cytoplasm Bud has same number of chromosomes as parent cell Hydra Yeast

Budding in Hydra http://www.youtube.com/watch?v=a5oHM jGqjyo

Regeneration Grow a new organism from a piece of another Regrow body parts Can be done because these cell are undifferentiated (not specialized)

Regeneration Planaria Earthworm Seastar

Seastar Regeneration http://www.youtube.com/watch?v=f7cXe WxxfD4&NR=1&feature=fvwp

Sporulation Multicellular organisms Spores released Grow into new organism Bread Mold

Vegetative Propagation Asexual reproduction in plants New plants will develop from roots, stems, and leaves of parent plant

Bulbs Enlarged underground stem Examples: Tulips, onions, garlic

Tuber Enlarged underground stem with buds (eyes) Example: potato

Runner Stem runs along ground New plants form Example: strawberry

Rhizome “mass of roots” Example: ginger

Cutting Stem or leaf is placed in ground New plant grows Example: geranium

Grafting Stem of one plant attached to cut end of another No blending

Layering Stems form roots where it touches soil

Results of Asexual Reproduction Offspring are genetically identical to parent Same DNA Same number of chromosomes Same characteristics

Cloning Artificial way to make an identical genetic copy Sheep, pigs, cats…

Steps of Cloning Take a parent cell nucleus & remove it Take an egg cell from a female and remove the nucleus Take the nucleus from the parent cell and put it into the egg cell Implant the egg cell into a female for development

Microdissection tools are used to remove nucleus from the cells

1. What happens to the nuclear membrane during prophase? 2. During which phase does DNA replicate? 3. Explain why anaphase is significant. 4. Describe the differences between mitosis in plant and animal cells.