Cell Reproduction Mitosis & Meiosis

PART ONE Mitosisor (cloning more of me)

Purpose of Mitosis To make identical cells so that an individual can……………………… To make identical cells so that an individual can………………………

Why would I want identical cells? replace damaged or old cells replace damaged or old cells grow grow

Why can’t I grow just by my cells getting bigger? If a cell is too big, nutrients cannot get into and out of the cell fast enough (membrane is too small compared to contents of cell—i.e. not enough doors) If a cell is too big, nutrients cannot get into and out of the cell fast enough (membrane is too small compared to contents of cell—i.e. not enough doors) Materials cannot diffuse through the interior of the cell fast enough. Materials cannot diffuse through the interior of the cell fast enough.

What vocabulary do I need to know to understand Mitosis. At rest DNA is CHROMATIN. At rest DNA is CHROMATIN. Dividing DNA forms CHROMOSOMES. Dividing DNA forms CHROMOSOMES. AND THEY LOOK VERY DIFFERENT.

THE TWO FACES OF DNA How do chromatin and chromosomes look different? How do chromatin and chromosomes look different?

The Chromosome Draw and label a chromosome. of the same chromosome

Where sister chromatids come from.

Becoming a duplicated chromosome

Human Chromosomes

The puppeteer stuff Spindle Fibers: strings that are attached to the centromers Spindle Fibers: strings that are attached to the centromers Centrioles: in animals, small paired structures that migrate to each pole during mitosis Centrioles: in animals, small paired structures that migrate to each pole during mitosis

The Cell Cycle Go to Cells Alive Go to Cells Alive Watch the animation several times Watch the animation several times What are the 3 stages of Interphase (not the Mitosis part)? What are the 3 stages of Interphase (not the Mitosis part)? Draw a circle (representing the cell cycle) Draw a circle (representing the cell cycle) Label the stages (M, G 1, S & G 2 ) Label the stages (M, G 1, S & G 2 ) List what happens in each stage List what happens in each stage

The Cell Cycle Observe each stage of the cell cycle Observe each stage of the cell cycle

Phases of Mitosis P-M-A-T P-M-A-T Prophase Prophase Metaphase Metaphase Anaphase Anaphase Telophase Telophase

Animal Cell Mitosis Watch the animation until you can explain what is happening. Watch the animation until you can explain what is happening.

Prophase Nuclear membrane disappears Nuclear membrane disappears Chromosomes and spindle fibers form Chromosomes and spindle fibers form

Metaphase Chromsomes line up in the MIDDLE Chromsomes line up in the MIDDLE Spindle fibers attach to chromosomes Spindle fibers attach to chromosomes

Anaphase Chromosomes are pulled APART by the spindle fibers Chromosomes are pulled APART by the spindle fibers

Telophase Nuclear membrane reappears Nuclear membrane reappears Cell begins to split into two Cell begins to split into two

Cytokinesis The cytoplasm splits The cytoplasm splits Two new cells are formed Two new cells are formed

Review….Just look at the pictures

Mitosis Animations