mitosis september (5*3)+2-9/3, 2009 objectives: describe the five phases of mitosis. explain why...
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MitosisSeptember (5*3)+2-9/3, 2009 Objectives:
Describe the five phases of mitosis. Explain why mitosis produces two identical
cells. Catalyst:
How do organisms grow? What happens in interphase?
Homework: Finish independent practice worksheet
Definitions – In case you missed them…
Sex cells = sperm and eggs Somatic cells = everything else
in your body DNA = instructions for how a cell
should run (it’s what makes you “you”)
Chromosome = coils of DNA. Look like Xs.
Catalyst Review
How do organisms grow? They create new cells! One cell divides into two The new cell is an exact copy of the previous cell
This process is called mitosis
Catalyst Review
What happens in interphase? Cells do their normal cell things
Heart cells beat Plant cells photosynthesizeEye cells let you seeSkin cells protect you from stuff
outside your body When cells are ready to divide, make
an exact copy of their DNA
Catalyst Review
Remember… Somatic (body) cells normally have 23 pairs of chromosomes2N = 2 PAIRS
When they are ready to divide, they make copies of their DNA4N = 4 PAIRS
Mitosis CHALLENGE! Are you up for it?
Arrange the four pictures in order that makes sense to you and your group!
There will be a prize for the group that gets the correct answer AND can explain why they chose this order.
Remember: In mitosis, a somatic cell creates an exact copy of itself.
Pull out the sheet you picked up this morning You can take notes on this sheet.
Stage #1: Interphase
Normally cells are 2N (two copies of each chromosome)
When cells are ready to divide, the cell’s DNA doubles Cell becomes 4N
(four copies of each chromosome)
Chromosome Pairs
In interphase, chromosomes duplicate and form pairs
When a chromosome is in a pair, it is called a chromatid
Stage #1: Interphase
Phase #2: Prophase
Chromatids attach to each other
Centrioles move to opposite ends of the cell Barrel-shaped organelle,
you’ll see what it does in a second
Nuclear membrane breaks Allows chromatids to
move freely
Sister chromatids line up in the center of the cell
Spindles shoot out of centrioles, and attach to sister chromatids
WHY would sister chromatids line up at the metaphase plate?!?!?!
Phase #3: Metaphase
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Phase #3: Metaphase
Spindles pull sister chromatids apart to opposite ends of the cell
WHY would sister chromatids move to opposite ends of the cell?!?!?!
Phase #4: Anaphase
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Phase #4: Anaphase
Nuclear membrane reforms
Spindle breaks apart Cleavage furrow
forms, “pinching” the cell in half
WHY would the cleavage furrow split the cell in half?!?!?!
Phase #5: Telophase
Phase #1: Interphase
Now we have two identical cells!!!
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Phase #5: Telophase
Animal Mitosis -- Review
Interphase
Prophase
Metaphase
Anaphase
Telophase
Interphase
Plant Mitosis -- ReviewInterphase
Prophase
Metaphase
Anaphase
Telophase
Interphase
WOW MR. JHAVERI YOU RULE!!!
THANKS MR. JHAVERI FOR THE SWEET MOVIE!!!
IInterphasePProphaseMMetaphaseAAnaphaseTTelophase
II PPaintaint MMany any AAmazingmazing TT--shirtsshirts
WHO’S PAYING ATTENTION?
What type of cell does mitosis occur in?
What is the starting point of mitosis? What are the end products of mitosis?
What are the names of the stages of mitosis?
Guided Practice
Today, we will move around the classroom to answer questions on the board. You have 10 seconds to get to each spot.
-In the middle of the classroom- Interphase -By the group folders- Prophase -By the computer- Metaphase -By Mr. McKnight’s room- Anaphase -By the door- Telophase
What phase is this?
-In the middle of the classroom- Interphase -By the group folders- Prophase -By the computer- Metaphase -By Mr. McKnight’s room- Anaphase -By the door- Telophase
What phase is this?
-In the middle of the classroom- Interphase -By the group folders- Prophase -By the computer- Metaphase -By Mr. McKnight’s room- Anaphase -By the door- Telophase
What phase is this?
-In the middle of the classroom- Interphase -By the group folders- Prophase -By the computer- Metaphase -By Mr. McKnight’s room- Anaphase -By the door- Telophase
What phase is this?
-In the middle of the classroom- Interphase -By the group folders- Prophase -By the computer- Metaphase -By Mr. McKnight’s room- Anaphase -By the door- Telophase
What phase is this?
-In the middle of the classroom- Interphase -By the group folders- Prophase -By the computer- Metaphase -By Mr. McKnight’s room- Anaphase -By the door- Telophase
Chromosomes line up in the middle of the cell
What phase is this?
-In the middle of the classroom- Interphase -By the group folders- Prophase -By the computer- Metaphase -By Mr. McKnight’s room- Anaphase -By the door- Telophase
Cleavage furrow forms, pinching the cell in half.
What phase is this?
-In the middle of the classroom- Interphase -By the group folders- Prophase -By the computer- Metaphase -By Mr. McKnight’s room- Anaphase -By the door- Telophase
In between cell divisions, when the cell does its thaaaaang.
What phase is this?
-In the middle of the classroom- Interphase -By the group folders- Prophase -By the computer- Metaphase -By Mr. McKnight’s room- Anaphase -By the door- Telophase
When chromosomes are pulled to opposite sides of the cell.
What phase occurs AFTER the following? -In the middle of the classroom- Interphase -By the group folders- Prophase -By the computer- Metaphase -By Mr. McKnight’s room- Anaphase -By the door- Telophase
Chromatids attach to each other and centrioles begin to move to opposite sides of the cell.
What phase occurs AFTER the following? -In the middle of the classroom- Interphase -By the group folders- Prophase -By the computer- Metaphase -By Mr. McKnight’s room- Anaphase -By the door- Telophase
Chromosomes line up in the middle of the cell.
What phase occurs AFTER the following? -In the middle of the classroom- Interphase -By the group folders- Prophase -By the computer- Metaphase -By Mr. McKnight’s room- Anaphase -By the door- Telophase
Chromatids are pulled apart to opposite sides of the cell.
Conclusion
I Paint Many Amazing T-shirts! Prophase- chromatids attach to each
other Metaphase- chromatids line up in the
middle of the cell Anaphase- chromatids are pulled to
opposite ends of the cell Telophase- cleavage furrow forms and
pinches off two cells Mitosis ends up with two identical cells!
Exit Question
What are the phases of mitosis in order? What must occur before mitosis (think
DNA)?