Mitosis and

Meiosis

The Cell Cycle• DNA: contains the

information that tells a cell how to make proteins.

• Chromosomes: coiled structure of DNA and protein that forms in the cell nucleus during cell division.

Prokaryotic Cells• Binary Fission: the simple cell

division in which one cell splits into two; used by bacteria.

•Homologous chromosomes: chromosomes with matching information.

•Chromotids: identical copies of a chromosome.

•Centromere: The region that holds chromotids together when a chromosome is duplicated.

MITOSIS• Nuclear division in a eukaryotic cell in which each cell receives a copy of the original chromosomes.

Remember…….

• There are 3 STAGES in this process

• Interphase• Mitosis• Cytokinesis

Four phases of Mitosis

ProphaseMetaphaseAnaphaseTelophase

Interphase•The time in between cell division

Interphase

• THE CELL GROWS TO ITS MATURE SIZE

• THE CELL MAKES A COPY OF ITS DNA CHROMATIN-(threadlike form of dna)

• IT PREPARES TO DIVIDE

Prophase(phase 1)• Nuclear membrane

breaks apart• Chromosomes become

rodlike.• Centrioles move to

opposite sides of cell.• Fibers form between

two pairs of centrioles

Metaphase(phase 2)

• Chromosomes line up along equator (middle) of the cell.

• Spindle fibers attach through the centromere

Anaphase(phase 3)

• Chromotids separate and are pulled to opposite side of cell by the fibers attached to centrioles

Telophase(phase 4)

• Nuclear membrane forms around two sets of chromosomes.

• Fibers disappear

Cytokinesis• Cytoplasm

splits in two.

• Result: two identical cell