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Cellular Reproduction

Cellular Reproduction. Chromosomes. Contain genetic information – DNA DNA is arranged in segments called genes Determine characteristics, or traits Humans have 46 chromosomes in their cells – 23 from each parent. Chromosomes.

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Cellular Reproduction

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  1. Cellular Reproduction

  2. Chromosomes • Contain genetic information – DNA • DNA is arranged in segments called genes • Determine characteristics, or traits • Humans have 46 chromosomes in their cells – 23 from each parent

  3. Chromosomes • Exist as chromatin prior to cell division - relaxed form of DNA in the cell’s nucleus

  4. Chromosomes Centromere: at the center of the chromosome where the sister chromatids attach Sister chromatids: Each half of the X, contains identical copies of DNA

  5. HUMAN CHROMOSOMES

  6. The Cell Cycle • Cells reproduce by growing and dividing • WHY?? • Cell division prevents the cell from becoming too large • To replace other cells • For asexual reproduction • To allow multicellular organisms to grow 3 Main Stages: Interphase Mitosis Cytokinesis

  7. The Cell Cycle

  8. Interphase • G1: The cell is growing, carrying out normal cell functions, and preparing to replicate DNA. Occurs immediately after the cell divides. • S: The cell copies its DNA in preparation for cell division. • G2: The cell prepares for the division of its nucleus.

  9. Mitosis • Process that divides the nucleus of one cell into two nuclei • Purpose is to create two daughter cells with identical genetic information • Each daughter cell receives the exact same # and type of chromosomes, it’s like photocopying the cell!

  10. Prophase • Beginning phase, the longest phase • Chromatin tightens, or coils, into chromosomes • In this phase the chromosomes are shaped like an X • Nuclear envelope disappears • Centrioles migrate to poles • Spindle fibers form

  11. Metaphase • Changing phase, one of the shortest stages • Chromosomes are pulled to center of cell and lined up • Ensures there are accurate copies of the chromosomes

  12. Anaphase • Anew phase • The spindle fibers pull the sister chromatids apart into two identical chromosomes • The chromosomes are pulled to opposite ends of the cell

  13. Telophase • Ending phase • Chromosomes reach the poles of the cell and begin to unwind • Two new nuclear membranes begin to form • Nuclei reappear

  14. It’s not over yet!

  15. Cytokinesis • Towards the end of mitosis, the cell undergoes cytokinesis • This divides the cytoplasm • The cytoplasm is pinched (the furrow) • Creates two new cells

  16. Animal Cell - Mitosis

  17. Plant Cell - Mitosis

  18. Chromosomes

  19. The Cell Cycle

  20. The Cell Cycle Interphase Prophase Metaphase Anaphase Telophase Cytokinesis IPray More At The Church!

  21. Cell Cycle Regulation • The cell cycle has built-in checkpoints that monitor the cycle and can stop it if something goes wrong.

  22. Abnormal Cell Cycle • CANCER: the uncontrolled growth and division of cells • Cancer cell can kill an organism by crowding out normal cells, resulting in the loss of tissue function

  23. Cancer The cancer cell cycle is much faster than the normal cell cycle: Chicken stomach cells Interphase: 16 minutes Prophase: 15 minutes Metaphase: 2 minutes Anaphase: 1 minute Telophase: 3 minutes • Interphase: 120 minutes • Prophase: 60 minutes • Metaphase: 10 minutes • Anaphase: 3 minutes • Telophase: 12 minutes

  24. Causes The changes that occur in the regulation of cell growth and division of cancer cells are due to mutations. • Inherited • Carcinogens • Radiation

  25. Apoptosis • Programmed cell death • Cells going through this apoptosis actually shrink and shrivel in a controlled process

  26. Cell Death

  27. Stem Cells • Unspecialized cells that can develop into specialized cells when under the right conditions

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