Mitosis Objectives•Explain how cells produce more cells•Describe the process of mitosis

Vocabulary• cell cycle-the life cycle of a cell

• chromosome- two DNA molecules held together by a centromere

• homologous chromosomes- similar chromosomes (46 in human body)

• mitosis- the process of chromosome separation

• Cytokinesis- the division of cytoplasm to form two daughter cells

Mitosis

What is it?•The process of cell division that forms two new nuclei, each of which has the same number of chromosomes

Copying DNA (Interphase)• Before mitosis begins,

chromosomes are copied

• Each chromosome is then two chromatids

Phase I: Prophase• Nuclear membrane

dissolves• Chromosomes condense

into rodlike structures• Centrioles move to

opposite ends of the cell and spindle fibers stretch across the cell

Phase II: Metaphase• Chromosomes line up

along the equator of the cell

• Homologous chromosomes pair up

Phase III: Anaphase• The chromatids (after

each chromosome is duplicated, the two copies are called this)separate and move to opposite sides of the cell

Phase IV: Telephase• A nuclear membrane forms

around each set of chromosomes

• The chromosomes unwind

• Mitosis is complete

Cytokinesis• In cells that lack a cell

wall, the cell pinches in two.

• In cells that have a cell wall, a cell plate forms between the two new cells.

Mitosis…

Phases at same time…

Mitosis