Mitosis

• Cell Cycle

Period of time from one division to the nextUnicellular division results in formation of new individuals of the species

Multicellular division results in replacement of old or damaged cells

Process by which the nucleus divides while maintaining number of chromosomes

Division of the cytoplasm

Asexual Reproduction

Reproduction that only involves one parentso therefore no special reproductive organsare needed

Cell Cycle

Mitosis

Cytokinesis

Nuclear DNA wound around proteins knownas histones

Condensed rolls of chromatin that are able to be seen during mitosis (rod-like structures)

There are 5 phases in MITOSIS

Interphase

MetaphaseProphase

AnaphaseTelophase

Chromatin

Chromosomes

Interphase Known as “resting phase”

•Cells grow in size by producing more nucleic acids, proteins,and cellular organelles

•Chromosomes make copies of themselves, but they can’t be •seen

•Nucleus of the cell is contained within the nuclear envelope

•Centrioles are present and duplicate themselves

Prophase•Double chromosomes become visible - Chromatid

•Chromosomes are 2 sister chromatids connected by a centromere

Centromere

Sister Chromatids

•At the beginning, centrioles move to opposite poles

•Aster (star shaped fibers) extend = microtubules•Spindle fibers attach (to centromere to pull away chromatids toopposite sides of the cell)

•By the end, the nuclear envelope and nucleus have disappeared

EARLY LATE

DON’T DRAW

Metaphase•Centromeres line up on the equator (middle= metaphase plate)

•By the end, the centromeres divide and pull the daughter chromosomes to opposite sides of the cell

•Half of each chromosome goes to the opposite side of the cell

Anaphase•Daughter chromosomes move to opposite sides of cell (poles)•Movement is accomplished by the microtubules•Movement occurs by shortening of the microtubules

Telophase•Chromosomes uncoil and return to previous shape (threadlike)

•Nuclear membrane and nuclei reform

NOTE: Cytokinesis begins during late anaphase and finishes during telophase

An easy way to remember theorder of the phases in mitosisis to think:

I PUNCHED MYAUNT TILLY!!

She had it coming!!

Same as mitosis in animals except:• Plants have no centrioles – spindle fibers take their place• Asters do not form• Cell wall does not pinch because it is too rigid• Cell plate divides the cell into two