Bellwork Tuesday 11/29
*Test this Friday
1. What is the cell doing during interphase?
Agenda:
1. Finish Notes
2. Q&A worksheet
3. Mitosis skit
Interphase
1) Interphase
• Cell is not dividing
– Doing its normal job
• Just before it’s time for a cell to divide
– Its chromosomes duplicate (form pairs)
and Prophase starts
Prophase
2) Prophase
• Chromosomes form pairs
– Connected by Centromere
– Nuclear membrane & nucleolus disintegrate
– Spindle forms
• Spindle organizes mitosis
• Spindle = fibers in a football shape
Spindle
Centromere
Chromosome
Metaphase
3) Metaphase
• Chromosome pairs line up in middle
• Each chromosome attached to spindle fiber
Anaphase
4) Anaphase
• Pairs of chromosomes are pulled apart
– By spindle fibers
Telophase
5) Telophase
• Chromosomes “regroup” at opposite poles
– Half go to each pole
• Nuclear membrane & Nucleolus re-form
• Spindle breaks down
– No longer needed
• Cytokinesis occurs
Centriole:
Organelle that
Pulls the spindle fibers
Centriole!
• Cytokinesis
– Division of cytoplasm & organelles
– Animal cells “pinch” in middle
– Keeps pinching until 2 daughter cells form
• Daughter cells must be identical to original cell
•
•
•
•
Prophase = Prephase, the beginning
Metaphase: Meet in the middle
Anaphase: Apart
Telophase: chromosomes go to
“telophone poles”
• Interphase: Intermission (not actually part of
mitosis)
Prophase
Metaphase
Interphase
Telophase
Anaphase
Count how many cells in each of the 5 stages
Interphase, prophase, metaphase, anaphase, telophase
Joke?
Why is interphase the favorite stage of
athlete’s foot?
Because it always falls in between mitosis
Twilight mitosis?
• http://www.youtube.com/watch?v=sOM_u1
PY0s0
Q&A worksheet
Skit
• You will be doing a skit showing the 5
stages of cell division
• Skit should at least include:
– Narrator: explains what is happening
– Chromosomes: should pair up when they
duplicate
– Spindle fibers: I will provide string
– Other parts you think are necessary
• Groups of 6, 7, or 8