Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Cell Division QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Why do we grow? Do our cells get bigger? NO: organisms grow because they produce more cells, not larger ones. A baby’s cells are the same size as an adult’s, there are just less of them. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Cell division Before a cell grows too large, it divides into two “daughter cells.” Before it divides, it must copy its genetic material so that both new daughter cells have a complete set of DNA. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Chromosomes: coiled up DNA Located in the nucleus Become visible ONLY during cell division Organisms have different numbers of them: humans have 46. The cell cycle: Interphase: G1 phase: cell growth S phase: DNA replication Cells increase in size, make new proteins & organelles Chromosomes are copied, new DNA molecules made G2 phase: preparation for mitosis Shortest phase, organelles &molecules needed for mitosis are made M phase (MITOSIS): division of the nucleus and cytoplasm into two daughter cells QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Mitosis phases: PMAT QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Prophase QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. First/longest phase (5060% of total time to do mitosis) Chromosomes become visible Centrioles separate and position at opposite ends of the cell Spindle fibers form Chromosomes attach to the spindle fibers Nuclear envelope breaks down Metaphase Lasts only minutes Chromosomes line up in the center of the cell QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Anaphase Copied chromosomes separate and begin to move toward opposite ends of the cell QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Telophase Chromosomes disperse --become a tangle of material rather than distinct chromatids Nuclear envelopes begin to form around each clump of chromosomes Spindles break apart QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Cytokinesis (very end of Telophase) Cytoplasm divides In animals the cell membrane pinches in In plants a new cell wall forms QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Mitosis Poster Copy figure 10-5 on pages 246-247 in your book onto a large poster paper Draw each stage//copy what is happening to the cell at each stage Must use color