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