MITOSIS

How somatic (non-sex cells) divide and multiply.

Interphase the cell gets itself ready for mitosis the phase of the cell cycle in which the cell

spends the majority of its time and performs the majority of its purposes including preparation for cell division

In preparation for cell division, it increases its size and makes a copy of its DNA

the cell obtains nutrients, grows, reads its DNA

Prophase

the chromosomes become visible

the centrosomes start to move away f rom each other

the nuclear envelope starts to disperse

the spindle begins to f orm

the nucleoli disappear

Chromatin present in the nucleus starts to condense and it can be

seen through the light microscope as chromosomes. The nucleolus

disappears. I t begins to move to opposite poles of the cell and

fibers extend f rom the centromeres.

Prophase

Prometaphase

Prometaphase

tetrads become connected to the spindle fibers by kinetochores

the nuclear envelope f ragments

Microtubules emerging f rom the centromeres at the poles (ends)

of the spindle reach the chromosomes

each sister chromatid has a protein structure called a

kinetochore

Some of the spindle microtubules attach to the kinetochores,

throwing the chromosomes into agitated motion

The nuclear membrane will be dissolved and it indicates the start

of prometaphase stage. Kinetochores will be created because of

the attachment of proteins to the centromeres. The

chromosomes begin its movement when Microtubules attach at

the kinetochores.

MetaphaseMetaphase plate

Centrosome at one spindle pole

Spindle

Metaphase

the alignment of chromosomes at the center of the cell

the separation of sister chromatids to opposite mitotic spindle poles

the centrosomes are now at opposite poles of the cell

Spindle fibers align the chromosomes along the middle of the cell nucleus named metaphase plate

Anaphase

Daughter chromosomes

Anaphase

the chromatids separate and move toward the spindle poles

Anaphase begins when the duplicated centromeres of each pair of

sister chromatids separate

At the end of anaphase, a complete set of chromosomes are

assembled at each pole of the cell.

The chromosome pairs separate at the kinetochores and move to

opposite sides of the cell.

Telophase and Cytokinesis

Telophase and Cytokinesis

The polar fibers continue to lengthen

Nuclei (plural f orm of nucleus) begin to f orm at opposite poles

The nuclear envelopes of these nuclei are f ormed f rom remnant

pieces of the parent cell's nuclear envelope

Nucleoli (plural f orm of nucleolus) also reappear

Chromatin fibers of chromosomes uncoil

Af ter these changes, telophase is complete and the genetic

"contents" of one cell have been divided equally into two

Cytokinesis, the division of the original cell's cytoplasm, begins

prior to the end of mitosis and completes shortly af ter telophase

I n animal cells, cytokinesis involves involves the f ormation of a

cleavage f urrow, which pinches the cell in two

At the end of cytokinesis, there are two distinct daughter cells

MITOSIS

The two daughter cells now become parent cells

and each produce two more daughter cell. This

process continues to repeat