Mitosis: The Mystery of Cell Division

Objectives When you complete this program you should be able to: 1. Define the term Mitosis. 2. List and describe the stages of mitosis. 3. Identify cells in various stages of the cell cycle using a microscope.

Why is Mitosis Necessary? 1. The parent cell is too fat (too much volume) compared to its skin (surface area) 2. Wastes do not exit quickly 3. Nutrients do not enter quickly 4. Essentially – divide of DIE!

Cell Cycle Cell Cycle can be defined as the life span of the cell. The cell cycle consists of… 1. Interphase 2. Mitosis Remember IPMAT!

IPMAT – in the order of the letters

Division is Vital to Survival

1.Cell gets fat, swells. 2.It madly copies its DNA in this phase in preparation for the inevitable cell division Interphase

Prophase 1.Centrioles go to the POLES or ends of the cell 2.Nuclear membrane begins to dissolve 3.Centrioles start casting out MITOTIC SPINDLE or NET

Metaphase – think “M” for MIddle 1.Chromosomes line up in the middle of the cell 2.Note that each chromosome has doubled and has two pairs of individual chromatids 3.Mommy version or Daddy version of the chromosome is pulled to the pole of the cell 4.No nuclear membrane!!!!!!

ANAPHASE 1.Chromatids move to the poles of cell 2.Spindle fibres hauled in by the centrioles 3.Equal distribution of DNA is the objective

Telophase 1.Chromosomes reach the poles 2.Furrow appears between cells about to divide 3.Cytoplasm is equally distributed to the daughter cells 4.Mitochondria also distributed

The process of division The appearance of two separate daughter cells follows shortly after the completion of this mitotic process.

Onion Root Tips – a blazing area of Mitosis Activity

Summary The cell cycle is the life span of the cell. Interphase is the first step in the cell cycle. Normal cell growth and DNA replication occur during interphase. Prophase is the beginning of mitosis. The replicated chromosomes become visible in this phase. The nuclear membrane disappears Metaphase follows prophase and is the stage in which the lining up of sister chromatids occurs at the metaphase plate.

Summary Cont. Anaphase is the stage of mitosis in which the chromosomes begin moving to the poles of the cell. Telophase marks the end of the mitotic process. The two new daughter cells will now enter Interphase and begin the cell cycle over again.

Need to See it all Again? You want to know this Quiz quiz quiz quiz Hint, hint, hint, hint Know all the phases You have been … informed ….