tailieunhanh - Lecture Biology: Chapter 12 - Niel Campbell, Jane Reece

This chapter introduce to the cell cycle. After completing this unit, you should be able to: Describe the structural organization of the prokaryotic genome and the eukaryotic genome; list the phases of the cell cycle; describe the sequence of events during each phase; list the phases of mitosis and describe the events characteristic of each phase;. | Chapter 12 The Cell Cycle In unicellular organisms, division of one cell reproduces the entire organism. Multicellular organisms depend on cell division for: Development from a fertilized cell Growth Repair Cell division is an integral part of the cell cycle, the life of a cell from formation to its own division. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Continuity of Life is Based on Cell Division Fig. 12-2 100 µm 200 µm 20 µm (a) Reproduction (b) Growth and development (c) Tissue renewal Repair Functions of Cell Division Figure The functions of cell division Concept : Mitotic Cell Division results in genetically identical daughter cells Most cell division is mitotic and results in daughter cells with identical genetic information, DNA. A special type of meiotic cell division produces nonidentical daughter cells (gametes, or sperm and egg cells). Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Cellular Organization of the Genetic Material All the DNA in a cell constitutes the cell’s genome. A genome can consist of a single DNA molecule (common in prokaryotic cells) or a number of DNA molecules (common in eukaryotic cells) DNA molecules in a cell are packaged into chromosomes. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Fig. 12-3 20 µm Figure Eukaryotic chromosomes Every eukaryotic species has a characteristic number of chromosomes in each cell nucleus. Somatic cells (2n) (body cells) have two sets (pairs) of chromosomes. Gametes (n) (reproductive cells: sperm and eggs) have half as many chromosomes as somatic cells. Eukaryotic chromosomes consist of chromatin, a complex of DNA and protein that condenses during cell division. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Distribution of Chromosomes During Eukaryotic Cell Division In preparation for cell division, DNA is replicated and the chromosomes . | Chapter 12 The Cell Cycle In unicellular organisms, division of one cell reproduces the entire organism. Multicellular organisms depend on cell division for: Development from a fertilized cell Growth Repair Cell division is an integral part of the cell cycle, the life of a cell from formation to its own division. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Continuity of Life is Based on Cell Division Fig. 12-2 100 µm 200 µm 20 µm (a) Reproduction (b) Growth and development (c) Tissue renewal Repair Functions of Cell Division Figure The functions of cell division Concept : Mitotic Cell Division results in genetically identical daughter cells Most cell division is mitotic and results in daughter cells with identical genetic information, DNA. A special type of meiotic cell division produces nonidentical daughter cells (gametes, or sperm and egg cells). Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings .