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

AnaphaseTelophase

Interphase

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_u1PY0s0

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