Transcript 10-2 Cell Division - Pleasanton Unified School District

Chapter 10
Cell Growth & Division
10-2 Cell Division
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Chromosomes
• Carry Genetic Information From One
Generation of Cell to the Next Generation
of Cells
• Made Up Of:
DNA + Protein
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Chromosomes
Every Organism Has A Specific
Number Of Chromosomes
Fruit Flys = 8
Carrots = 18
Humans = 46
Giraffe
= 30
King Crab = 208
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Chromosomes
• Not Visible Except During Division
• Well Before Division They Duplicate
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Chromosomes
• Chromatids
– Just Before Division Chromosomes Condense
Into Compact, Visible Structures Called
Chromatids
• Centromere
– Each Chromosome Has Two, Identical
Chromatids Connected By A Centromere
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Chromosomes
Chromatid A
Kenitophore
Copy of Chromatid A
Centromere
Microtubules
or
Spindle Fibers
Chromatid A
Copy of Chromatid A
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
The Cell Cycle
Key Concept:
During The Cell Cycle:
A Cell Grows
Prepares For Division
Divides To Form Two Daughter
Cells
Each Daughter Cell Then Begins
The Cycle Again
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Cell Cycle
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Interphase
Time In-Between Cell
Divisions
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Cell Division or M phase
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Events Of The Cell Cycle
Interphase
May Be Quite Long
Divided Into 3 Parts
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
The 3 Parts of Interphase
G1 Phase
Cell Grows In Size
Synthesize New Proteins &
Organelles
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
The 3 Parts of Interphase
S Phase
Chromosomes Are Replicated
Once This Phase Begins The
Cell Completes Division
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
The 3 Parts of Interphase
G2 Phase
Organelles & Proteins
Required For Mitosis Are
Produced
Cell Is Now Ready To Enter
M Phase (Mitosis)
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Mitosis
Key Concept:
Biologists Divide The Events Of
Mitosis Into Four Phases:
1.Prophase
2.Metaphase
3.Anaphase
4.Telophase
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Prophase
1st & Longest
Phase
 Chromosomes
Become Visible
 Centrioles
Separate & Take
Up Position On
Opposite Sides
Of The Nucleus
 Spindle Begins
To Form
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Prophase
In Animals
Spindle Fibers
Attach To
Centromere On
Each Chromatid
In Plants
No Centromere,
Spindle Fibers
Still Form From
Centrosomes
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Late Prophase
• Nucleolus
Disappears
• Nuclear
Envelope
Breaks Down
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Metaphase
Short
Just A Few Minutes
• Chromosomes Line
Up Across Center Of
The Cell
• Microtubules
Connect The
Centromere To The
Poles Of The Spindle
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Anaphase
• Centromeres
Separate
• Sister Chromatids
Separate
• Each Set Of
Chromosomes
Pulled To Their
Poles
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Telophase
• Chromosomes
Disperse
• New Nuclear
Envelopes Form
• Spindle Breaks
Apart
• Nucleolus
Reforms
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Cytokinesis
• There Are Now Two
Nuclei In One Cell
• Cytokinesis Is The
Division Of The
Cytoplasm Into Two
Cells
• The Cell Membrane
Is Drawn Inward
Until The Cell
Pinches Into Two
Equal Parts
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Cytokinesis In Plants
A New Cell Plate
Forms In The Middle
Of The Cell Which
Attaches To, And
Becomes Part Of,
The Cell Wall
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT