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Today’s Agenda:

Today’s Agenda:. Journal Question : What is a chromosome? *1. Lecture : Introduction to Chromosomes, Mitosis & Meiosis ( slide 47 ) 2. Packet for Unit (Bring to class every period) (Buy Color Pencils & Glue Stick) 3. Today’s Focus: DNA Characteristics & Chromosome Structure

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Today’s Agenda:

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  1. Today’s Agenda: Journal Question : What is a chromosome? *1. Lecture: Introduction to Chromosomes, Mitosis & Meiosis (slide 47) 2. Packet for Unit (Bring to class every period) (Buy Color Pencils & Glue Stick) 3. Today’s Focus: DNA Characteristics & Chromosome Structure 4. Color first picture in packet: DNA: The Double Helix. 5. Video: Genetics 6. Exam before break

  2. Cellular Reproduction Dr. Rick Woodward

  3. DNA Characteristics A. Long thin molecule (double helix) that stores genetic information (Unit of Heredity) “Blueprint for Life” B. Location: Nucleus of the Cell

  4. DNA Characteristics C. Function: Controls & Directs Activities of the Cell D. In humans there are 6 billion pairs of nucleotides - If a cell were the size of a basketball, the DNA would stretch for 40 miles!

  5. Chromosome Structure A. DNA is coiled into very compact structures called chromosomes. B. Chromosomes are rod-shaped structures of DNA & Protein.

  6. Chromosome Structure C. A histone is a protein molecule that DNA wraps around during chromosome formation.

  7. Anatomy of a Chromosome

  8. Chromosome Number A. Each species has a specific number of chromosomes in each cell. B. For each chromosome there are two copies or one pair (total): (1) one from the mother (2) one from father

  9. Chromosome Number C. Humans have 46 chromosomes (23 pairs) D. Gorillas have 48 chromosomes (24 pairs) E. Your neighbor’s cat has 32 chromosomes (16 pairs)

  10. Genetically Engineered Cats 1. Some day these cats may rule the planet with the assistance of militant cows. 2. What you are about see is classified top secret by the federal government.

  11. Genetically Modified Cats Martial Arts Super Cats

  12. Extreme Kung Fu Cat

  13. Bi-Pedal Snow Cat Dodging a Bullet

  14. Karaoke Cats Transmitting Code

  15. Gaming Nintendo Wii Cat Genetically superior gaming skills

  16. Laser Cats

  17. Diabolical Joker Cat

  18. What is a Chromatid? A. It is one of two identical parts of a chromosome

  19. What is a Centromere? A. Each chromosome has a central constricted region called a centromere that serves as an attachment point.

  20. What is a telomere? A. The telomeres protect the tips of the chromosomes from damage.

  21. Sex Chromosomes A. Determines the sex of an organism. B. In humans: XX = female XY = male

  22. Autosomes A. An autosome is a chromosome that is not a sex chromosome.

  23. Karyotype: A Picture of an Individual’s Chromosomes

  24. Homologous Chromosomes A. Every cell of an organism produced by sexual reproduction has two copies of each autosome.

  25. Homologous Chromosomes B. We get one copy of each autosome from each parent. C. Two copies of each chromosome are called homologous pairs of chromosomes.

  26. *Haploid (1n) vs. Diploid (2n) Cells A. Haploid Cells (1n) (1) One set of chromosomes (2) Sperm cells (3) Egg cells B. Diploid Cells (2n) (1) Two sets of chromosomes (2) All non-reproductive cells. (3) Zygote/Fertilized Egg C. Red blood cells do not have any chromosomes because they are missing a nucleus

  27. Prokaryote vs. Eukaryote A. Prokaryotes lack membrane-bound organelles. 1. Bacteria B. Eukaryotes have membrane-bound organelles (mitochondria, nucleus, etc.) 1. Plants & Animals

  28. Cell Division in Prokaryotes BINARY FISSION is the division of a prokaryotic cell (bacteria) into two identical cells! 1. DNA copied 2. Cell begins to divide 3. Two identical haploid cells.

  29. CELL DIVISION IN EUKARYOTES • Both the cytoplasm and the nucleus divide. • Two types: 1. MITOSIS (clones) A. Reproduction of unicellular organisms B. Addition of cells to a tissue or organ. 2. MEIOSIS (gametes/sex cells) A. 1/2 the chromosome number B. Cells recombine in sexual reproduction.

  30. DNA Replication The DNA must be copied and then divided exactly so that each cell gets an identical copy.

  31. Cellular Reproduction (Mitosis) A. Growth is the result of a cell’s ability to reproduce itself.

  32. Cellular Reproduction (Mitosis) (1) New body cells are produced from other, already existing cells; when one cell becomes two. (Recall “The Cell Theory”)

  33. Cellular Reproduction (Mitosis) (2) Examples: Skin cells, intestinal tracts cells are continuously being replaced.

  34. Cellular Reproduction (Mitosis) B. New cells are produced that contain the same genetic information as the cells from which they came.

  35. Cellular Reproduction C. Mitosis = The process that produces and replaces body cells; exact copies. (i.e. skin cells) 1. Continuance of an individual’s growth throughout life.

  36. Cellular Reproduction D. Meiosis = The process that produces reproductive cells needed for the formation of new individuals. 1. Continuance of the species.

  37. Cellular Reproduction I. Life from Life = Cells from Cells A. Disproving Spontaneous Generation: (1668, Francesco Redi’s controlled experiment showed that maggots do not spontaneously generate from decaying meat.)

  38. Cellular Reproduction B. Louis Pasteur disproved the theory that microorganisms are not spontaneously generated from air. 1. Used a flask with a long S-shaped neck, boiled broth. 2. Pasteurization is the partial sterilization of a substance by increasing the temperature of that substance to destroy objectionable organisms (i.e. bacteria).

  39. Cellular Reproduction C. Reproduction of Body Cells (Mitosis) 1. Cell reproduction occurs when parent cells divide. A. Two new daughter cells arise from each parent cell.

  40. Cellular Reproduction B. After reaching full development, an organism needs new cells to: (1) repair damaged tissue, replace cells that are lost from outer surfaces (skin cells) and resist disease.

  41. Cellular Reproduction C. It is estimated that 25 million cell divisions occur every second in the adult human body.

  42. Cellular Reproduction D. Rapid cell division or cell growth that is out of control is called cancer. 1. Suffix: -oma

  43. Looking at Cancer Cells

  44. The Cell Cycle

  45. Cellular Reproduction 2. The Cell Cycle (Interphase + Mitosis = The Cell Cycle) “Interphase” (1) Interphase (non-reproducing stage that follows when cell reproduction/replication is complete)

  46. Today’s Agenda • Today’s Agenda: Journal Questions: a. What are the parts of the cell cycle? b. What is the difference between mitosis and meiosis? *1. Lecture: Cellular Reproduction & The Stages of Mitosis (Slide 91) 2. Work on packet: Karyotype Activity 3. Homework: Finish packet and study 4. Exam this Thursday (12/16/10)

  47. Cellular Reproduction (2) DNA Synthesis & Duplication occur during Interphase.

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