Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Cell Reproduction
Document related concepts
Transcript
Cell Reproduction Chromosomes Mitosis Meiosis Two Types of Cells Prokaryotes • No nucleus • No Organelles • Unicellular but can form filaments and colonies • Smaller—1-5 μm across • Example: bacteria • Binary fission is the process prokaryotes use to divide Eukaryotes • Has nucleus • Has organelles • Can be either unicellular or multicellular • Larger—10-100 μm across • Examples: animals, plants, fungi, yeast • Mitosis ONLY occurs in EUKARYOTES Why do cells need to divide and reproduce in eukaryotes? 1. Repair of tissue (like a broken bone) Why do cells need to divide and reproduce in eukaryotes? 2. So the organism can grow Like a baby….their body is growing very, very fast Tree Growth CANCER So….cells divide and make new cells It’s called MITOSIS Everybody say it…. MITOSIS Cell Division • Cell Division is the process by which cells reproduce. • information in the cell is contained in genes → genes code for proteins → proteins carry out cellular functions • Each body cell that results from cell division must have an exact copy of the DNA in the original cell. Chromosomes Chromosome Structure Chromosome Structure Chromosome Structure Chromosome Structure Chromosome Number Mitosis • Mitosis: the division of the cell nucleus in which the chromosomes in the parent cell divide into two identical sets • In somatic cells (body cells), the number of cells is increased without changing the information contained in the DNA or the amount of DNA in those cells. Cell Cycle Overview Important Structures Equator Polar Fibers Asters Kinetechore Centrioles Kinetechore Fibers Mitosis in Plants Cleavage Furrow & Cell Plate Meiosis Overview Meiosis Genetic Recombination • Genetic Recombination: the process that results in chromosomes being arranged in many different ways • crossing-over between homologues or chromatids • homologous pairs separate independently in meiosis I • sister chromatids separate independently in meiosis II CROSSING V E R CROSSING V E R Independent Assortment Karyotype Diploid vs. Haploid • Diploid (2n): a cell that contains both chromosomes of a homologous pair • Humans = 46 (somatic cells: body cells) • Haploid (n): a cell that has only one chromosome of each homologous pair • Humans = 23 (gametes: egg and sperm) Mitosis
