The Cell Cycle

P

M

A

T

C

C

I

Non sex cell (somatic) life cycle and division

INTERPHASE = G1,S,G2

G1=Growth and normal

metabolic functions

S= DNA replication

G2= More growth, energy

storage to prepare for

division.

M=Mitotic division (has

phases) cell suspends all

metabolic activities

Anatomy of a chromosome• Chromatin = Relaxed DNA

• Chromatid = A copy of DNA (one half of a

duplicated chromosome)

• Chromosome = Condensed DNA – 2 types

– Duplicated = copy + original (looks like an x)

– Unduplicated = only 1 copy (looks like a l)

Prophase• Original DNA (chromatin) and

copies (chromatid) start to

condense (into chromosomes).

• The two centrioles move

toward the opposite ends of

the cell.

• The nuclear envelope and

nucleolus also start to break

up.

• The mitotic apparatus forms

Metaphase • The spindle fibers

attach the original

and copied DNA

• All the

chromosomes are

lined up at the

equator (center)

of the cell.

Anaphase• Sister chromatids

separate from each

other along the

centromere and each

moves away from the

other to opposite sides

(poles) of the cell.

• They move along the

spindle fibers.

Telophase

• The 2 new cells pinch (cleavage furrow)

in animal cells or a cell plate forms in

plant cells.

• The DNA relaxes back into chromatin.

• New nuclear envelopes form in each cell

and the nucleolus is reformed.

Cytokinesis

• Now that the DNA is

all copied and moved

to daughter nuclei,

the rest of the cell

divides. (organelles,

cytoplasm)

Let’s watch!

• http://wormclassroom.org/files/worm/Cell

Division.mov

• http://www.youtube.com/watch?v=0oJZ

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• http://www.youtube.com/watch?v=DD3I

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