Cell Division in Prokaryotes and Eukaryotes Chapter 10, Section 2 Pg. 244 - 249

Cell Division in Prokaryotes Prokaryotes reproduce through binary fission. 3 steps: Cell duplicates its chromosome. Cell doubles in size. DNA is divided and 2 new cells are formed. Two new cells are identical to one another.

Cell Division in Eukaryotes All eukaryotes go through the cell cycle. Cell cycle – different stages of life for cells Made up of 2 parts: Interphase – time between divisions G1 – cell grows to its mature size S (synthesis) – chromosomes are copied G2 – cell prepares for division M phase – cell division Mitosis – chromosomes in nucleus divide Cytokinesis – the rest of the cell divides Cells can leave the cell cycle. Some cells stop dividing (ex: nerve cells) These cells are said to be in G0

Cell Division in Eukaryotes Cell division happens during the M phase of cell cycle Made of 2 parts: Mitosis – nucleus divides Prophase Metaphase Anaphase Telophase Cytokinesis – cytoplasm divides

Prophase Chromsomes coil up and condense Nuclear membrane breaks down 1st time chromosomes are visible Nuclear membrane breaks down Centrosomes appear and move to opposite ends of the cell Spindle fibers attach to each chromosome Attach at the centromere

Metaphase Meta = middle Spindle fibers move chromosomes Chromosomes line up along the middle of the cell

Anaphase Spindle fibers shorten and move the chromosomes across the cell Chromosomes separate, and chromatids are pulled apart Chromatids move to opposite ends of the cell

Telophase Chromosomes reach ends of the cell Spindle fibers detach and disassemble Nuclear membrane reforms around each set of chromosomes Nucleolus reforms One large cell with two identical nuclei Cytokinesis happens next Splits the rest of the cell Different in plants and animals

Cytokinesis in Animal Cells Cell membrane pinches in forming a cleavage furrow until cells are separated. The cytoskeleton causes this to happen.

Cytokinesis in Plants Vesicles from Golgi fuse together forming a membrane-bound cell wall called a cell plate. Eventually it grows to separate the cells.

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