THE PHASES OF MITOSIS

Claire Stevens

Interphase– Growth and preparation

DNA is in its chromatin state

Cell grows biggerThe cell is making protein necessary for its survival

Interphase--Replication

It may not look like anything has changed in the cell but….

An enzyme separates the DNA into two stands here

DNA unwinds

The original DNA strand is a sort of template for a new side to form around

Most organelles will be replicated during this stage

Interphase-Continuing growth and preparation

The cell is continuing to grow and make proteins

The chromatin has not coiled up into chromosomes as of yet

Early prophase

Spindle fibers start to form from the centrioles

The nucleolus has disappeared from the nucleus

The nuclear membrane begins to break down

DNA coils up into chromosomes

Early prophase-continue

The centrioles with the spindle fibers move towards the poles of the cell

The nuclear membrane continues to break down

Early prophase- continue

The centrioles and spindle fibers are now almost at the poles of the cell

The cell membrane has almost completely disintegrated

Late prophase

The spindle fibers are now fully formed.

The spindle fibers attach to the chromosomes at the centromere

The nuclear membrane has completely disappeared

The centrioles are completely at the poles

Late prophase- continue

The spindle fibers are starting to pull the chromosomes into a line across the equator of the cell

Late prophase- continue

The chromosomes are continuing to straighten out

Metaphase

The spindle fibers pull the chromosomes into a line across the middle of the cell

Metaphase- continue

The chromosomes are starting to be pulled apart at the centromere

The spindle fibers are starting to retract

Metaphase- continue

The centromere is close to breaking

The spindle fibers continue to retract

Anaphase

Spindle fibers are continuing to retract and pull back towards the centrioles

Chromosomes break apart at the centromere and the sister chromatids are pull toward opposite poles of the cell

Anaphase- continue

Spindle fibers are retracting

Sister chromatids are starting to pull away from the spindle fibers The cell starting to

get ready to divide

Anaphase- continue

Sister chromatids detach from the spindle fibers and come together with their partners

Nuclear membrane starts to form around each set of sister chromatids

Spindle fibers are almost completely retracted into the centriole

Telophase

Set of chromosomes at each end of the cell

The nucleolus reappears within each nucleus

A nuclear membrane forms around the chromosomes

Spindle fibers disappear

The cell is now ready to divide

Telophase- continue

The chromosomes are starting to uncoil into chromatin

The cell is getting closer and closer to division

Telophase- continue

The chromosomes uncoil further and are now almost entirely in the chromatin state

The cell membrane is getting stronger and more complete

The cell is ready to split in two

CytokenesisTwo nuclei are moved into two daughter cells

Chromosomes have returned entirely to the state of chromatin

The two new cells are identical to the original one

The two new cells are ready to go through the life cycle again!

Complete cell membrane

Bibliography

• http://ineedmoving.com/siteadmin/interphase-cell-diagram

• http://www.macroevolution.net/prophase-i.html

• http://www.phschool.com/science/biology_place/biocoach/meiosis/teloi.html

• http://morganterhune3a.edublogs.org/2011/11/14/cell-cycle-sequencing/

• http://www.flickr.com/photos/26457459@N02/3264922970/

• http://seximexibio3.blogspot.ca/

• http://s322991969.websitehome.co.uk/wsb5822978901/interphase-labeled-diagram

• http://www.ied.edu.hk/biotech/eng/classrm/class_gene2.html