What is Mitosis? A form of cell division. Asexual reproduction in unicellular organisms. Growth and Repair in multicellular organisms.

Types of Asexual Reproduction Fission The equal splitting of a cell through mitosis to form two new cells. Budding The unequal splitting of a cell through mitosis to form on parent cell and one daughter cell.

Why do Cells Reproduce? 1.To make more organisms of the same species (unicellular organisms). 2.To grow (multicellular organisms) 3.To repair damaged tissues (multicellular organisms).

Why does Mitosis occur? When cells get too big they can no longer get enough nutrients through the cell membrane in order to sustain it’s entire self. In other words it does not have enough surface area to diffuse in enough nutrients or diffuse out all wastes.

Mitosis can be explained in Phases Regular cell activity and Mitosis can be explained in 5 basic phases. The phases are Interphase, Prophase, Metaphase, Anaphase and Telophase.

Interphase Normal activities of the cell are performed. Chromatin is doubled at the end of this phase. Chromatin Interphase – In Between

Prophase Chromatin condenses into chromosomes. Centrioles migrate to the poles. Spindle fibers begin to form. Nuclear membrane begins to break down. Prophase - “Preparing” Doubled Chromosomes Sister Chromatids

Metaphase Chromosomes line up on the equatorial plane. Metaphase – “Middle” Pole Equator

Anaphase Spindle Fibers pull the Sister chromatids apart. Single chromosomes move toward the poles. Anaphase – “Away” or “Apart”

Telophase Single stranded chromosomes arrive at the poles. Nuclear membranes form. Cytokinesis (pinching in) begins. Telophase – “Two”

How can we remember all these phases? I. P. M. A. T.

Animations Mitosis Animation Mitosis by a spanish Robert Miles Pokemon Mitosis

MeiosisMitosis End result Normally four cells, each with half the number of chromosomes as the parent Two cells, having the same number of chromosomes as the parent Function Sexual reproduction, production of gametes (sex cells) Cellular reproduction, growth, repair, asexual reproduction Where does it happen?Animals, fungi, plants, protistsAll eukaryotic organisms Steps Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II, Telophase II Prophase, Metaphase, Anaphase, Telophase Genetically same as parent? NoUsually Crossing over happens?Yes, in Prophase ISometimes Pairing of homologous chromosomes? YesNo CytokinesisOccurs in Telophase I and Telophase IIOccurs in Telophase Centromeres split Does not occur in Anaphase I, but occurs in Anaphase II Occurs in Anaphase Meiosis vs. mitosis In order to understand meiosis, a comparison to mitosis is helpful. The table below shows the differences between meiosis and mitosis.