The Cell Cycle

WELCOME TO MY MAGIC SHOW!

First, I am going to make a very small ball turn into a

larger ball.

Then, I am going to make the larger ball split into two smaller identical balls.

(Oooooh, aaaaah!!!)

Interphase

•The stage that the cell spends most of it’s life in.

•Consists of 3 phases:•G1 phase•S phase•G2 phase

G1 phase

•Point in a cell’s life where it does most of it’s growing.

•The cell increases in size because of protein, DNA and organelle synthesis.

S Phase

•Stage of cell life in which chromosomes are replicated.

•DNA is copied during DNA replication.

chromatin

duplicatedchromosome

G2 phase

•This is the preparation phase for mitosis.

•Organelles and proteins needed for mitosis are synthesized.

Overview of Interphase• The cell is synthesizing the

materials that are vital for growth, development, and cell division (mitosis).

• DNA is copied.• mRNA, proteins and organelles are

made.• The cell is increasing in size and

preparing to divide.

Mitosis

•The “BIG SHOW”!•Occurs in body cells.• Is needed when the cell

becomes too large due to the growth that occurs during interphase.

•Consists of 4 phases.

4 Phases of mitosis:

•Prophase•Metaphase•Anaphase•Telophase

Now for my next trick I will make not 1, but 2 things disappear and 2 things

appear!

Prophase

•The chromatin condenses to form chromosomes.

•Centrioles separate and spindle fibers start to form.

•The nucleolus and nuclear membrane disappear.

What did the talented and impressive magician make appear? Disappear?

Magic trick

Appear

1. Chromosomes

2. Spindle fibers

Disappear

1.Nucleolus

2. Nuclear membrane

Metaphase•The chromosomes line up in

the MIDDLE of the cell .

•M is for Meta-, M is for Middle

•Mitotic spindle fibers connect the centromeres to the centrioles.

Anaphase•The sister chromatids

separate becoming individual chromosomes.

•The chromosomes move to opposite poles of the cell.

•A is for Ana-, A is for APART!

Telophase

•The chromosomes and spindle fibers disappear.

•The nuclear membrane and nucleolus re-appear.

•The two new cells are almost completely formed.

telophase

• Telophase is the reverse of prophase!

• The two things the magician made disappear he now makes re-appear!

• The two things the magician made appear magically disappear!

Cytokinesis

•The division of cytoplasm (cytokinesis) is now complete and we have two new identical cells.

•We call these cells daughter cells!

So did you like the show?

Is this individual male or female?

Stages of mitosis in onion root tip cells

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     

                                                                                                                                            

Cell Division Animation

• http://www.loci.wisc.edu/outreach/bioclips/CDBio.html