Who has larger cells?

Which has larger cells a mouse or an elephant?

CELLS ARE SMALL!

Why do we need to make more cells?Why do we need to make more cells?

From One Cell to Many Sea Urchin Cell Division

Why do we need to make more cells?

Why do we need to make more cells?Why do we need to make more cells?

Why are we one hundred trillion SMALL cells and not one hundred LARGE cells? 100,000,000,000,000 cells because ,000,000,000,000 cells because....

They need to be small!

1cm 3 = small Cell 3cm 3 = big Cell Sodium Hydroxide will React with phenolphthalein Inside agar cube

DRAW WHAT YOU THINK WILL HAPPEN

Result It takes much longer for molecules to get where they need to go if a cell is too big!

Surface area: Surface area: effects the rate of food, O 2, H 2 O, and wastes moving in & out of the cell effects the rate of food, O 2, H 2 O, and wastes moving in & out of the cell Volume: Volume: effects the rate at which food, O 2, H 2 O are used and waste is produced effects the rate at which food, O 2, H 2 O are used and waste is produced

Parent Cell Daughter Cells

Common Locations for Cell Division Skin Skin Sperm cells Sperm cells Blood cells days Blood cells days Liver- sometimes Liver- sometimes

Cells that Never Divide (In G 0 phase ) Cardiac cells Cardiac cells Kidney Kidney Nerve cells Nerve cells

Checkpoints G1 Checkpoint: -Cell size -DNA can be replicated G2 Checkpoint -Cell size -DNA intact -DNA duplicated M checkpoint - Chromosomes are properly attached to the spindle fibers.

1.Repair the damage OR 2. Self-destruct APOPTOSIS (Programmed Cell Death) What happens if the cell cannot pass through the checkpoint?

Parent Cell Daughter Cells

MITOSIS Parent Cell Daughter Cells

Interphase Prophase Metaphase Anaphase Telophase

Chromosome= Sister Chromatids

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MITOSIS MITOSIS Video Parent Cell Daughter Cells

Mitosis( cell cycle) Videos for Flipbook hill.com/sites/ /student_view0/chapter2/animation__mitosi s_and_cytokinesis.html 9QB0 com/watch?v=lf9rcqifx34å hill.com/sites/ /student_view0/chapter2/animation__mitosi s_and_cytokinesis.html 9QB0 com/watch?v=lf9rcqifx34 ( cell cycle)

ONION ROOT TIP

Twilight DOES IT TOO!

INTERPHASE

PROPHASE

METAPHASE

ANAPHASE

TELOPHASE

I. Interphase: “I-ball” NOT A PHASE OF MITOSIS 90% of the time! 90% of the time! 1. Gap 1 cell grows, doubles organelles 1. Gap 1 cell grows, doubles organelles 2. Synthesis Duplication of the DNA 2. Synthesis Duplication of the DNA 3. Gap 2 cell grows

Steps of Mitosis: (PMAT) Prophase Metaphase Anaphase Telophase sis--WHOLE.htm

1. Prophase- Chromatin fibers condense into chromosomes Chromatin fibers condense into chromosomes Nuclear membrane breaks down Nuclear membrane breaks down Spindle of microtubules forms from centrioles [animals only] Spindle of microtubules forms from centrioles [animals only]

2. Metaphase- “ middle ” Spindle fibers from centrioles attach to centromeres Spindle fibers from centrioles attach to centromeres Spindles move Chromosomes to line up in the middle Spindles move Chromosomes to line up in the middle Centriole Spindle

3. Anaphase: “ away phase ”, form “ A ’ s ” Spindle fibers contract Spindle fibers contract Pull sister chromatids apart Pull sister chromatids apart Chromosomes move towards opposite ends Chromosomes move towards opposite ends Each side has own copy of DNA Each side has own copy of DNA Individualchromosomes

4. Telophase- “ end phase ” Nuclear membranes reform at each pole Nuclear membranes reform at each pole Chromosomes unwind Chromosomes unwind Spindle disappears Spindle disappears

Cytokinesis (NOT a phase of Mitosis) During cytokinesis, the cytoplasm cuts in half Each daughter cell has an identical set of duplicate chromosomes

Cytokinesis in Plants In plants, a structure known as the cell plate forms midway between the divided nuclei.