Mitosis animation: http://www.youtube.com/watch?v=2WwIKdyBN_s&feature=related

Influenced by Function (ex/eggs), Surface Area, Volume, and Mass

Must be large enough to have enough DNA for cell to function

Can not be too large- metabolic processes need to be to occur Surface area to volume ratio decreases

Everything passes through plasma membrane!

If a cell wants to make a duplicate of itself, it first must copy its DNA (part of a chromosome).

Why is this important? So every cell has the correct amount of DNA!

ASEXUAL RPRODUCTION! Reproduction from a single parent Inherit genes of that parent only –

CLONING!! Ex/ bacteria

MITosis takes the cell and Makes It Two (diploid)

From the cell’s point of view: mITosis results in Identical Twins

Clyde Freeman Herreid – Dept. of Biological Sciences: Buffalo State Univ. of New York

MAJOR EVENTS IN MITOSISMAJOR EVENTS IN MITOSIS

Mitosis animations: http://www.youtube.com/watch?v=VlN7K1-9QB0

VOCABULARYVOCABULARY

ChromosomeChromosome = Carries genes (DNA) from 1 cell to another during cell division. Contain DNA from both parents

Humans have 46 Chromosomes!

23 sex chromosomes ( Just ½ the #)

DiploidDiploid = Two copies of each chromosome, one paternal, one maternal

Haploid: Haploid: 1 copy of each chromosome(sex cells: must combine with other

sex cells)

DNA is replicated along with organelles and other cellular components and the cell prepares for division.

DNA is replicated so the daughter cells have the

correct number of chromosomes

THE CELL CYCLE: INTERPHASETHE CELL CYCLE: INTERPHASE

3 stagesSeries of

events that take place

as they grow and

divide

Animal cell Plant cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

Longest Phase

http://www.bioweb.uncc.edu/1110Lab/notes/notes1/lab6.htm

The DNA recoils, and the chromosomes condense (visible); the nuclear membrane disappears, and the mitotic spindles begin to form.

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

Animal cellAnimal cell Plant cellPlant cell

The chromosomes line up the middle of the cell with the help of spindle fibers attached to the centromere of each replicated chromosome.

http://www.bioweb.uncc.edu/1110Lab/notes/notes1/lab6.htm

Animal cell Plant cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

The chromosomes split in the middle and the sister chromatids are pulled by the spindle fibers to opposite poles of the cell.

Identical sets of chromosomes

Animal cell Plant cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

The chromosomes, along with the cytoplasm and its organelles and membranes are divided into 2 portions. This diagram shows the end of telophase.

http://www.bioweb.uncc.edu/1110Lab/notes/notes1/lab6.htm

Animal cell Plant cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

The actual splitting ofthe daughter cells into

two separate cells is called cytokinesis

-Occurs differently in both plant and animalCells.

http://www.bioweb.uncc.edu/1110Lab/notes/notes1/lab6.htm

2 diploid cells (start with diploid, end with diploid!)

Genetically identical cells (clones)

In somatic cells, NOT gametes Only 1 division occurred

Meiosis animation: http://www.youtube.com/watch?v=D1_-mQS_FZ0&NR=1

Diploid Haploid Germ cell (gametes)

Somatic cell

Interphase Prophase Metaphase Anaphase Telophase Cytokinesis

MEIOSIS

Fusion of two gametes, sex cells,

(1 form each parent) to produce

a single zygote.

Sexual reproduction:

Introduces greater genetic variation

Same as in Mitosis:

-Cell cycle-G1, S, G2 stageshttp://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

-Chromosomes are visible, -Nuclear envelope disappears. -Centrioles begin to form spindle fibers (same as mitosis)

DIFFERENCE:

**Exchange of DNA occurs- “crossing over”. Chromosomes double** LONGEST PHASE!!!

When DNA is exchanged it contributes to genetic variation.

Crossing over occurs in different locations in each cell

-Nuclear membrane dissolves

-The homologous chromosomes attach to the spindle fibers.

-Lined up in center

*Mitosis differencehttp://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

The chromosomes (not chromatids) separate and move to opposite ends of the cell.

-Mitosis difference

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

The cell begins to divide into two daughter diploid cells.

**Each daughter cell can get any combination of maternal and paternal chromosomes.

Mitosis difference http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

No new chromosome replication occurs in Meiosis II

2 diploid cells (from meiosis 1) divide again

**No Interphase II

The cell has divided into two daughter cells.

Prophase II is identical to prophase of mitosis except that there is half the amount of chromosomes- nuclear membrane dissolves

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

As in Meiosis I, the chromosomes line up on the spindle fibers.

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

The two cells each begin to divide. As in Meiosis I, the chromosomes move to opposite ends of each cell.

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

As in Mitosis, the cells divide.

*4 haploid cells are made!

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

Diploid to haploid cells 4 haploid cells are made Gametes (sex cells) Genetically different cells, unique!

Sex cells have 23 chromosomes