Meiosis2C or not 2C

What is meiosis?A) A fancy dish served at Asian Fusion restaurants.

B) The name of the newest singing sensation.

C) The process by which haploid cells called gametes are formed.

Why is meiosis important?

A) Just because it is.

B) It allows the chromosome number to be halved.

C) Yo no se!

What is involved in meiosis?A) A series of steps similar to mitosis.

B) Haploid cells (gametes).

C) A lot of vowels.

D) Both A and B are correct.

What is a haploid cell?A) A cell that is happy.

B) A sex cell—egg or sperm.

C) A cell that has half the number of chromosomes as a somatic (body) cell.

D) Both B and C are correct.

Meiosis: The FactsProcess resulting in formation of

reproductive cells.Occurs using similar steps as mitosis.End product is 4 genetically different haploid

cells.Haploid cells are 1C.Diploid cells are 2C.

Occurs in two stages—Meiosis I and Meiosis II.Meiosis I – separates the tetrad resulting in

TWO cells.Meiosis II – separates the sister chromatids

resulting FOUR cells.

Meiosis – The CastHomologous

Chromosomes – (AKA Tetrad) pairs of similar but not

identical chromosomes. They code for the

same characteristic. One is inherited from

mother (pink) and other from father (blue).

Homologous Shoes?Look at your shoes.How can they compare

to homologous chromosomes?SistersSimilar but not identical

(left and right shoes) All shoes (in class)

No two pairs are identical Unique pairs of

chromosomes in the cells

Meosis – The CastChromatin – packed

genetic material

From oodle noodle to bow pasta!

Meiosis – The CastSister Chromatids =

one complete chromosome

1) Chromatid2) Centromere3) Short-Arm of

chromatid4) Long-Arm of

chromatid

Meiosis – The CastTetrad –formed during

meiosis I.These are PAIR of

sister chromatids. Called a tetrad

because there are FOUR chromatids present.

“Swapping” of genetic material between chromosomes occurs between tetrad.

A Tetrad of ShoesTwo pairs of shoes =

one tetrad

Each pair of shoes = one chromosome.

Each pair = sister chromatids

Each individual shoe = one chromatid.

Meiosis -- PreviewOccurs in two stages.Steps are very similar to mitosis.4 haploid cells are end product of meiosis II.Meiosis I and Meiosis II are similar.

Exceptions: DNA replication Does NOT occur in Meiosis II. TWO cells produced after Meiosis I and FOUR cells

after Meiosis II.

From Diploid to HaploidMeiosis I – results in TWO cells b/c TETRAD

has been separated.

Genetic information is “swapped” between maternal and paternal chromatids. This is called synapse.

From Diploid to HaploidMeiosis II – results in FOUR cells b/c sister

chromatids have been separated. New cell are genetically different due to cross

over.

Meiosis—Party Time!

SQUARE DANCING!!

Turkey in the CELLSQUARE DANCE MOVES/TERMS

Link arms – represents the centromere

Synapse – bump hips “crossing over”

Mosey – a cross between a skip and a gallop

Metaphase plate – the equator of the cell (it is the middle of

the room)Salute – wave and bow

Meiosis I – The Nitty GrittyProphase I – chromatin condense into

chromosomes, tetrads form, spindles formMetaphase I -- tetrads line up at the equator,

spindles attach to centromereAnaphase I – tetrads are pulled apart toward

the poles by spindle fibersTelophase I – cell splits completely producing

two daughter cells with one complete chromosome (sister chromatids)

Meiosis II – The ScoopMeiosis II – Repeats the steps as Meiosis I

with HALF as many chromosomes Prophase II – DNA does NOT replicate.Metaphase II–Sister Chromatids line up at

the equator.Anaphase II – Sister chromatids are pulled

toward the poles and separate.Telophase II – Cell splits 4 haploid cells are

formed, with 1 chromatid.

Meiosis – Cover Shot

Questions, Pictures, Autographs?

Thank You!!

Ya’ll come back now!

I hope you enjoyed theshow

and learned something.

Bibliography Beyonce

http://www.zimbio.com/picture/lihk6AfVkBL/Beyonce+Knowles Homologous Chromosomes

http://www.kdimages.com/discover/previews/916/90011467.JPG Chromatin

http://www.micro.magnet.fsu.edu/cells/nucleus/images/chromatinstructuresfigure1.jpg

Chromatid http://www.wpcontent.answcdn.com/wikipedia/commons/thumb/0/0b/chromosomes.ssvg/220px-Chromosome.sv

Tetrad http://www.synapses.co.uk/genetics/meiosis.html Meiosis Phases

http://1.bp.blogspot.com/-bRrXTfFkHTE/S1zINGEyw-I/AAAAAAACs/epEwg1sD.jpg

Meiosis vs Mitosis http://image.wistatutor.com/content/fundamental-unit-life/meiosis-and-mitosis-cell-division.jpeg

Meiosis Stain www.brown.edu/Courses/BIoo32/gentherp/meiosis.jpg Waving Hands http://1.thumbs.canstock.com/canstock0046569.jpg