Heh Heh Heh. . .Heh Heh Heh. . .Here’s your opener for today: Here’s your opener for today:

Copy it! Thursday, 3/10Copy it! Thursday, 3/10

What is the fastest way to What is the fastest way to determine the sex of a determine the sex of a chromosome?chromosome?

Pull down its Pull down its genesgenes!!!!!!

Just wanted to make sure you laughed and Just wanted to make sure you laughed and smiled today! ;) --Be Good! Ms. Lee smiled today! ;) --Be Good! Ms. Lee

5.2 KEY CONCEPT 5.2 KEY CONCEPT Cells divide during mitosis and

cytokinesis

WHY do your cells do MITOSIS?????

Cell division! Gotta make new cells!

Each new cell has own DNA, organelles, & cytoplasm!!!

Chromosomes!!! – DRAW Chromosomes!!! – DRAW IT!!!!IT!!!!

Condensed, duplicated chromosome

chromatid

telomere

centromere

telomere

•ChromatinChromatin = DNA + Protein!!! = DNA + Protein!!!•ChromatidChromatid = half a duplicated = half a duplicated chromosome!chromosome!•CentromereCentromere = holds together sister = holds together sister chromatidschromatids•TelomereTelomere = end; protects DNA, = end; protects DNA, doesn’t include genes!doesn’t include genes!

For these notes, copy the notes into the boxes—make For these notes, copy the notes into the boxes—make sure you label the phase too! Start @ #1...sure you label the phase too! Start @ #1...

Parent cellParent cell

centrioles

spindle fibers

centrosome

nucleus withDNA

• Normal stuff.

• Also, cell grows, copies organelles & DNA

1. Interphase1. Interphase

2. Prophase– Chromosomes condense (visible)Chromosomes condense (visible)– Nuclear membrane disappearsNuclear membrane disappears– Centrioles separate & spindle Centrioles separate & spindle

fibers extend from themfibers extend from them

3.Metaphase3.Metaphase

– Spindle fibers connectSpindle fibers connect to to centromere of each sister centromere of each sister chromatidchromatid

– Chromosomes move & line up Chromosomes move & line up across across MIDDLEMIDDLE of cell of cell

4. Anaphase4. Anaphase– Centromeres splitCentromeres split– Sister chromatids separate Sister chromatids separate & &

move to opposite polesmove to opposite poles

5. Telophase5. Telophase– Chromosomes uncoilChromosomes uncoil– nuclear membrane forms around the nuclear membrane forms around the

chromosomes at each ½ chromosomes at each ½ – Spindle fibers break downSpindle fibers break down

6. Cytokinesis6. Cytokinesis

= cytoplasm splits! = cytoplasm splits!

2 2 IDENTICALIDENTICAL (genetically) cells!!! (genetically) cells!!!

CytokinesisCytokinesis—extra info @ bottom of your —extra info @ bottom of your sheet...sheet...

– In animal cells, membrane pinches closed: In animal cells, membrane pinches closed: ““cleavage furrowcleavage furrow””

– In plant cells, a In plant cells, a cell platecell plate forms. forms.Vesicles, merge @ middle, forms from Vesicles, merge @ middle, forms from

inside outinside out

Hmm? Hmm?

Cells spend the majority of Cells spend the majority of their cell cycle in the phase their cell cycle in the phase where ‘normal stuff’ where ‘normal stuff’ happens...happens...

Hmmm....which phase?Hmmm....which phase?Parent cellParent cellcentrioles

spindle fibers

centrosome

nucleus withDNA

What’s the purpose of What’s the purpose of mitosis???mitosis???

To create 2 new, identical To create 2 new, identical daughter cells!!daughter cells!!

Which phase?????Which phase?????

Which phase?????Which phase?????

Parent cellParent cell

centrioles

spindle fibers

centrosome

nucleus withDNA

Which phase?????Which phase?????

Which phase?????Which phase?????

Which phase?????Which phase?????

Which phase?????Which phase?????

Don’t Forget...

• THIS Saturday, Cleaning up litter & recyclingTHIS Saturday, Cleaning up litter & recycling

@ Maybank Highway Bridge area, marsh...mud...fun! @ Maybank Highway Bridge area, marsh...mud...fun!

• Sign up on the sheetSign up on the sheet• Talk to me TOMORROW about where/when/what to Talk to me TOMORROW about where/when/what to

wear...wear...• FREEFREE TSHIRTS!! TSHIRTS!!• FREEFREE FOOD!! FOOD!!

““LIFE” or “Nature’s Most Amazing LIFE” or “Nature’s Most Amazing Events” or “Human Body: Pushing Events” or “Human Body: Pushing

the Limits” Videothe Limits” Video• YOU ARE YOU ARE

SOOOOOOOoooooooooooOOOOOOOOOOOOOSOOOOOOOoooooooooooOOOOOOOOOOOOOO LUCKY....because you’re so awesome! O LUCKY....because you’re so awesome!

• Vote—THIS IS A DEMOCRACY! Vote—THIS IS A DEMOCRACY! – Watch the video, write down as many fun Watch the video, write down as many fun

facts as you can.facts as you can.– At the end, give me a sentence…thumbs At the end, give me a sentence…thumbs

up or down, did you like it (for real…)up or down, did you like it (for real…)

• We’ll do microscope labs tomorrow. • Be good! • Happy Thursday!