BELL RINGER DIRECTIONS1. Make sure you each have:

1. One whiteboard2. One whiteboard marker3. One whiteboard eraser 4. One calculator

2. Answer all projected questions on your whiteboards and HIDE YOUR ANSWERS FROM YOUR FRIENDS UNTIL TOLD TO HOLD THEM UP.

3. Leave answers on the whiteboard until told to erase them.

In what stage of the cell cycle is this cell?

ANSWER: INTERPHASE

NOW list 2 major events that happen during interphase on your whiteboards.

Josef Reischig (author), CC BY SA 3.0, http://commons.wikimedia.org/wiki/File:Mitosis_(261_10)_Pressed;_root_meristem_of_Vicia_faba_(cells_in_anaphase,_prophase).jpg

Interphase Review

• Interphase is separated into 3 phases: G1, S, G2.

• Cell grows and develops during G1 and G2.

• Cell performs its designated function throughout

• DNA replicates to prepare for division during S. Creative Commons Attribution-Share Alike 2.5 Generic license,

http://commons.wikimedia.org/wiki/File:Schinterphase.jpg

In what stage of the cell cycle is this cell?

ANSWER: PROPHASE

NOW list 2 major events that happen during prophase on your whiteboards.

Josef Reischig (author), CC BY SA 3.0, http://commons.wikimedia.org/wiki/File:Mitosis_(261_03)_Pressed;_root_meristem_of_Vicia_faba_(cells_in_prophase,_metaphase).jpg

Prophase Review

• The chromatin condenses into visible chromosomes.

• The nuclear envelope disappears.

• Spindle fibers begin to form from the centrioles.

Creative Commons Attribution-Share Alike 2.5 Generic license, http://commons.wikimedia.org/wiki/File:Schprophase.jpg

In what stage of the cell cycle is this cell?

ANSWER: METAPHASE

NOW list 1 major events that happen during metaphase on your whiteboards.

Josef Reischig (author), CC BY SA 3.0, http://commons.wikimedia.org/wiki/File:Mitosis_(261_13)_Pressed;_root_meristem_of_onion_(cells_in_prophase,_metaphase,_anaphase,_telophase).jpg

Metaphase Review

• Chromosomes align themselves in the center of the cell along the metaphase plate.

• The spindle fibers are now attached to the centrioles of the chromosomes. Creative Commons Attribution 3.0 Unported license,

http://commons.wikimedia.org/wiki/File:Metaphase.svg

In what stage of the cell cycle is this cell?

ANSWER: ANAPHASE

NOW list 1 major events that happen during anaphase on your whiteboards.

Josef Reischig (author), CC BY SA 3.0, http://commons.wikimedia.org/wiki/File:Mitosis_(261_10)_Pressed;_root_meristem_of_Vicia_faba_(cells_in_anaphase,_prophase).jpg

Anaphase Review

• The sister chromatids separate and begin moving to opposite poles of the cell.

• The spindle fibers shorten, pulling the chromosomes apart.

Creative Commons Attribution-Share Alike 2.5 Generic license, http://commons.wikimedia.org/wiki/File:Schanaphase.png

In what stage of the cell cycle is this cell?

ANSWER: TELOPHASE

NOW list 2 major events that happen during telophase on your whiteboards.

Josef Reischig (author), CC BY SA 3.0, http://commons.wikimedia.org/wiki/File:Meiosis_(261_34).jpg

Telophase Review

• Chromosomes begin to “uncoil” back into chromatin.

• The nuclear envelopes begin to form again.

• A cleavage furrow (animal cells) or cell plate (plant cells) begin to form between the 2 new nuclei.

This image is in the public domain because its copyright has expired. From Grey’s Anatomy, http://commons.wikimedia.org/wiki/File:Telophase.jpg

In what stage of the cell cycle are these cells?

ANSWER: CYTOKINESIS

NOW list 2 major events that happen during cytokinesis on your whiteboards.

Josef Reischig (author), CC BY SA 3.0, http://commons.wikimedia.org/wiki/File:Mitosis_(261_10)_Pressed;_root_meristem_of_Vicia_faba_(cells_in_anaphase,_prophase).jpg

Cytokinesis Review

• Division of the cytoplasm

• The cleavage furrow pinches in all the way forming two distinct cells in animal cells.

• In plant cells, the cell plate fully forms separating the two new cells.

This work has been released to the public domain by its author, LadyofHats, http://commons.wikimedia.org/wiki/File:Mitotic_Cytokinesis.svg.

Percentage Practice

Miss G has a bag that contains 100 beads. 26 of the beads are blue, 34 of the beads are red, 18 of the beads are green, and 22 of the beads are yellow. What percentage of the beads are green?

ANSWER: 18% -- Pretty easy right? How how about this…

Percentage Practice

• Miss G decided to add 163 beads to her bag increasing her total number of beads to 263. In this new bag there are 72 blue beads, 65 red beads, 90 green beads, and 36 yellow beads. Now what percent of the beads are green?

ANSWER: 34.22% (90 green beads/263 total beads) X 100 = 34.22

Now lets look at an example using the cell cycle…

Percentage PracticeA student is observing an onion root tip under a microscope. He counts a total of 157 cells. 20 of the cells he counts are in anaphase. Using this data to form a prediction, how much time does this cell spend in anaphase? How many hours per day is the cell in anaphase?

ANSWER: 12.74% of the time. 24 x 0.1274 = 3.06, therefore this cell spends 3.06 hours each day in anaphase. What type of chart might you use to visualize how much time is spent in each stage of the cycle?

What you should see under the microscope!

Josef Reischig (author), CC BY SA 3.0, http://commons.wikimedia.org/wiki/File:Mitosis_(261_13)_Pressed;_root_meristem_of_onion_(cells_in_prophase,_metaphase,_anaphase,_telophase).jpg