CELL GROWTH REPRODUCTION Why are cells so small

CELL GROWTH & REPRODUCTION

Why are cells so small? § Small cells are efficient because they have a smaller surface to volume ratio § Exchange of oxygen, food and waste across the membrane is more efficient in small cells

Cell Vocab To Know § DNA- genetic material § Chromatin= loose DNA, like pasta § Chromosomes = condensed chromatin, they form when cell is ready to divide, look like an X § Chromosomes are made up of 2 sister chromatids held together in the middle by the centromere

The Life of a Cell § Cell Cycle = sequence of growth & division of a cell § 1. Interphase § 2. Cell Division § Mitosis § Cytokinesis

1. Interphase § Cell grows, majority of a cell’s life. Has 3 parts: §G 1: Cells grow and makes proteins §S: Chromosomes containing DNA are replicated (copied) §G 2: Cell prepares for division

2. Cell division § Mitosis- cell division § creates 2 daughter cells w/ identical DNA § Divided into 4 phases § § Prophase Metaphase Anaphase Telophase § Cytokinesis

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1. Prophase § Chromatin thickens and forms into visible chromosomes § Nuclear Envelope & Nucleolus break down § Centrioles (poles) at opposite ends of cell start sending out spindle fibers (fingers) between them

2. Metaphase § Chromosomes line up in the center of the cell § Spindle Fibers attach to the centromere of each chromosome and pulls them in the middle

3. Anaphase § Sister chromatids are pulled to the opposite ends (poles) of the cell

4. Telophase § Nuclear Envelope & Nucleolus re-form § Chromosomes appear as chromatin again § Mitosis ends § 2 daughter cells with identical DNA

Cytokinesis § Division of the cytoplasm Cleavage (pinch) in animal cells Cell Plate (new wall) in plant cells

Bellringer Tue, 11/24 1. Please list the 4 phases of mitosis. PMAT! 2. A chromosome is made up of_____ Reminders: LAB FEE NOW! HW #12 due Wed! Time’s Up! 30 4 3 2110 1 Minutes 2 3 4 5 6 7 8 9 Minute Seconds

Interphase Prophase Metaphase Anaphase Telophase