Mitosis

Catalyst:How do organisms grow?

What happens during interphase?Write in complete sentences!

Don’t talk during the Catalyst!

Objectives

By the end of the period, SWBAT…

Describe the five phases of mitosis

Explain why mitosis produces two identical cells

Definitions – In case you missed them… Sex cells = sperm and egg cells Somatic cells = all other cells in your body

DNA = genetic code that instructs the cell how to run (it’s what makes you “you”)

Chromosome = pieces of coiled DNA. They 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.

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 2N

Phase #2: Prophase

Sister chromatids attach to each other

Centrioles move to opposite ends of the cell

Nuclear membrane breaks Allows chromatids to move

freely

4N

Sister chromatids line up in the center of the cell (“metaphase plate”)

Spindles shoot out of centrioles, and attach to sister chromatids

WHY would sister chromatids line up at the metaphase plate?!?!?!

Phase #3: Metaphase 4N

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 4N

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 4N

Phase #1: Interphase

Now we have two identical cells!!!

2N

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. LY YOU RULE!!!

THANKS MR. LY 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 door into the classroom – Prophase By the stereo – Metaphase By the computers – Anaphase By the college poster – Telophase

Which phase is this?

In the middle of the classroom – Interphase By the door into the classroom – Prophase By the stereo – Metaphase By the computers – Anaphase By the college poster – Telophase

Which phase is this?

In the middle of the classroom – Interphase By the door into the classroom – Prophase By the stereo – Metaphase By the computers – Anaphase By the college poster – Telophase

Which phase is this?

In the middle of the classroom – Interphase By the door into the classroom – Prophase By the stereo – Metaphase By the computers – Anaphase By the college poster – Telophase

Which phase is this?

In the middle of the classroom – Interphase By the door into the classroom – Prophase By the stereo – Metaphase By the computers – Anaphase By the college poster – Telophase

Which phase is this?

In the middle of the classroom – Interphase By the door into the classroom – Prophase By the stereo – Metaphase By the computers – Anaphase By the college poster – Telophase

Chromosomes line up in the middle of the cell

Which phase is this?

In the middle of the classroom – Interphase By the door into the classroom – Prophase By the stereo – Metaphase By the computers – Anaphase By the college poster – Telophase

Cleavage furrow forms, pinching the cell in half.

Which phase is this?

In the middle of the classroom – Interphase By the door into the classroom – Prophase By the stereo – Metaphase By the computers – Anaphase By the college poster – Telophase

In between cell divisions, when the cell does its thaaaaang.

Which phase is this?

In the middle of the classroom – Interphase By the door into the classroom – Prophase By the stereo – Metaphase By the computers – Anaphase By the college poster – Telophase

When chromosomes are pulled to opposite sides of the cell.

Which phase occurs AFTER this? In the middle of the classroom – Interphase By the door into the classroom – Prophase By the stereo – Metaphase By the computers – Anaphase By the college poster – Telophase

Chromatids attach to each other and centrioles begin to move to opposite sides of the cell.

Which phase occurs AFTER this? In the middle of the classroom – Interphase By the door into the classroom – Prophase By the stereo – Metaphase By the computers – Anaphase By the college poster – Telophase

Chromosomes line up in the middle of the cell.

Which phase occurs AFTER this? In the middle of the classroom – Interphase By the door into the classroom – Prophase By the stereo – Metaphase By the computers – Anaphase By the college poster – 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)? Write in complete sentences!

Don’t talk during the Catalyst!