Cellular Reproduction Mitosis

I) Cell Division in Eukaryotes A) Eukaryotes use Mitosis to produce identical daughter cells by means of Asexual Reproduction B) Eukaryotes use Meiosis to produce a new mix of genes by means of Sexual Reproduction

II) Interphase (blue arrows) A) G 1 : Gap 1 1) Normal housekeeping 2) Basic cell functions 3) Is usual “stopping point” for cells B) S: Synthesis (copying) of DNA 1) Centrioles copied too C) G 2 : Gap 2 1) Preparation to divide before mitosis begins

III) M Phase (pink arrow) A) Prophase B) Metaphase C) Anaphase D) Telophase E) Cytokinesis (yellow)

IV) Mitosis: Early Stages

A) Prophase: 1)Early: nuclear envelope degrades, chromatin start to condense 2)Late: chromatin thickens (now called chromosomes) & matching chromosome pair-up (sister chromatids) 3)Spindle apparatus forms between the centrioles

IV) Mitosis: Early Stages B) Metaphase: 1)Spindle fibers attach to chromosomes at centromeres 2)Sister chromatids line up at cell equator

V) Mitosis: Late Stages

A) Anaphase: 1)Sister chromatids separate (back into chromosomes) at their centromeres 2)Chromosomes move to the cell’s poles

V) Mitosis: Late Stages B) Telophase: 1)Nuclear envelope reforms in each daughter cell & chromosomes uncoil back into chromatin. 2) Cytokinesis: separates two new cells by division of the cytoplasm & organelles

V) Mitosis: Late Stages C) Interphase: 1)Daughter cells are genetically identical to each other and the original parent cell, but they are smaller

VI) Animal Cell Cytokinesis A) Separation of the two daughter cells by the microtubules & microfilaments of the cytoskeleton

VII) Plant Cell Division & Cytokinesis A) Spindle forms without centrioles B) Golgi apparatus forms vesicles over the equatorial plate, forming a cell wall while splitting into two cells

VIII) Controls of Mitosis A) Reasons cells go through mitosis: 1) Growth 2) Repair 3) Replace old cells 4) Asexual reproduction

X) Cancer A)Cancer cells do not have a properly functioning cell cycle control system 1)They divide excessively & can invade other tissues of the body B)Tumor – abnormal mass of cells 1)Benign tumor – abnormal mass of essentially normal cells 2)Malignant tumor – mass of cancer cells capable of spreading into neighboring tissues C)Metastasis - spread of cancer cells beyond their original site

X) Cancer A)Cancer cells do not have a properly functioning cell cycle control system 1)They divide excessively & can invade other tissues of the body B)Tumor – abnormal mass of cells 1)Benign tumor – abnormal mass of essentially normal cells 2)Malignant tumor – mass of cancer cells capable of spreading into neighboring tissues C)Metastasis - spread of cancer cells beyond their original site

XI) Cell Division in Prokaryotes A) Prokaryotes undergo Binary Fission, producing identical daughter cells — type of Asexual Reproduction

XI) Cell Size A)Most cells are small 1)~1-100 micrometers ( μ m) 2)Nerve cells may be a meter or more in length 3)Most egg cells are large 4)Prokaryotic cells are about 1-10 μ m 5)Eukaryotic cells about μ m

XI) Cell Size B)Cells are limited in size by the ratio between their outer surface area (SA) & their inner volume (V). 1)Need sufficient (SA) to supply the cell with its needs & remove its wastes a)As size increases, (V) increases faster than (SA) 2)Larger the cell, longer it would take substances to reach organelles where they are needed