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Cell Division and Reproduction

Cell Division and Reproduction. Unit 7. warmup March 13 #. Chromosome DNA is coiled to conserve space in a structure called a chromosome. When the DNA copies to prepare for mitosis, the two copies are each called chromatids and are connected for a while in a doubled chromosome.

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Cell Division and Reproduction

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  1. Cell Division and Reproduction Unit 7

  2. warmup March 13 # Chromosome DNA is coiled to conserve space in a structure called a chromosome. When the DNA copies to prepare for mitosis, the two copies are each called chromatids and are connected for a while in a doubled chromosome. Turn in Warm-up journals today! Make sure EVERY page is NUBMERED and DATED!

  3. Cell surface area to volume ratios • http://www.youtube.com/watch?v=xuG4ZZ1GbzI&feature=related

  4. Reasons for Cell Division • 1. Maintain a workable volume to surface area ratio; volume increases faster than surface area in cells • a larger surface area: volume ratio is preferable. • 2. Growth- multicellular organisms must increase in the number of cells to grow • 3. Repair and replacement of cells lost due to injury or cell death requires cell division. Larger surface area: volume ratio Smaller surface area: volume ratio

  5. Warmup March. 14th #31 Meiosis A form of SEXUAL reproduction. This type of cell division creates gametes or sex cells. These are haploid or have ½ the number of chromosomes so that the zygote has the correct number after fertilization. Mitosis This type of ASEXUAL cell division makes exact copies of a cell. It is part of a cell’s life cycle, after normal growth. The phases of mitosis are Prophase, Metaphase, Anaphase, and Telophase. (PMAT) One parent cell divides to become two daughter cells.

  6. Cell Reproduction VideoTake notes, and you will be SUMMARIZING when we are finished watching • DNA (3 mins) • Mitosis (2:30) • Mitosis Phases (2:19)

  7. Mitosis Song • http://www.youtube.com/watch?v=HYKesI9jL8c

  8. Eukaryotic Cell Cycle • Interphase: Longest part of the cell cycle; DNA replication takes place, carries out life functions • Chromatin: condensed DNA and proteins, (will form a chromosome) • Chromatid: identical copies of DNA making up a duplicated chromosome, attached at centromere • Doubled chromosome: nicely packaged and duplicated DNA

  9. Interphase includes G1, Synthesis, G2 • Here is what’s happening in each phase

  10. Mitosis • Prophase: Chromosomes visible, spindles form • Metaphase: chromosomes move to middle (equator) of the cell • Anaphase: doubled chromosomes separate, chromatids move to opposite ends of cell • Telophase:spindles breakdown, nuclear envelope appears • Cytokinesis: Division of cytoplasm • Plant Cells: cell plate is produced and will become cell wall • Results:Results: Two identical cells that are diploid (2n) (have two of each chromosome- one from mother and one from father) • –The diploid number for our cells is 46 chromosomes

  11. Problems with Mitosis • Cancer: Uncontrolled cell division • A cancerous lung tumor • Benign when it is localized to one area, malignant when cancer cells are in blood stream and move to another part of the body

  12. Mitosis – Cut and Paste • Pg. 7E • Cut out the pictures and place them in the CORRECT order on a sheet of paper. • Make sure to read the directions and LABEL • Write the name of each phase under the picture. • ****On ONE SIDE (plant or animal cell side) describe what is happening in each phase

  13. Most Wanted Chromosome - Mr. Chrom.O.Some - DUE TUESDAY! • Mr. Chrom.O.Some is wanted and is in Mitosis County. You must join in on the search for Mr. Chrom.O.Some by completing the following.  • 1-Draw a picture of Mr. Chrom.O.Some • Write a story/description on the where abouts and happenings of Mr. Chrom.O.Some (during cell division) Include the following words in your story, and underline the words as you use them. • Chromosome • Spindle Fibers • Mitosis • Centromere • Chromatids • Cell division • Chromatin • 3- Although this is a creative project/story, it should make logical sense. I should be able to understand your story and clearly see that you understand the where abouts of a chromosome during cell division. • 4- You will be graded using the following criteria: • 8 points -creativity and neatness • 32 points-accuracy of story- 2 pts for each word above • (Do you have an understanding of the terms used?) • Interphase • Prophase • Metaphase • Anaphase • Telophase • Cytokinesis • Parent Cell • Daughter Cell • Identical

  14. Ticket out the Door • Identify the stages of the cell cycle in the picture. • 1.Interphase • 2. prophase • 3. metaphase • 4. anaphase • 5. telophase 6. List two examples of asexual reproduction and briefly EXPLAIN. 7. What is one ADVANTAGE of asexual reproduction? 8. What is one DISADVANTAGE of asexual reproduction?

  15. Types of Reproduction • Asexual: one source of genetic material, identical daughter cells • Advantages: reproduction is fast, less energy needed, no mate needed, • Disadvantages: lack of genetic variation (one thing could wipe out entire population)

  16. Types of Asexual reproduction • Binary Fission: cell divides into 2 equally sized cells • Budding: produce smaller cells than parents (ex. hydra and yeast) • Sporulation - produces spores

  17. Types of asexual reproduction • Vegetative propagation: a portion of one plant produces a new identical plant • Regeneration: part of animal is repaired through cell division

  18. Discovery Education Video Notes Write down one COMPLETE sentence OR draw a picture for each topic covered in the movie. • Introduction (2:30) • Cell theory (3 mins) • DNA (3 mins) • Mitosis (2:30) • Mitosis Phases (2:19) • Bacteria and Binary fission (2 mins) • Bacterial Reproduction (2 mins) • Protists and Binary Fission (1:19) • Budding (2 mins) • Sporulation (1 min) • Regeneration (2 min) • Vegetative Propagation (3 mins) • Parthenogenesis (1 min) • Viral Reproduction (2 mins)

  19. Warm-up March 15th # 32 Asexual Reproduction One parent One set of genetic material Fast cell division Identical offspring (babies) Sexual Reproduction Two sets of genetic material Slower reproduction Variation (differences) in offspring (babies)

  20. Ticket Out the Door • 1. List two examples of asexual reproduction and briefly EXPLAIN. • 2. What is one ADVANTAGE of asexual reproduction? • 3. What is one DISADVANTAGE of asexual reproduction? • 3. How is sexual reproduction different from asexual reproduction?

  21. Whitefish Mitosis Slides

  22. Ticket out the door • 1. Give two examples of asexual reproduction and briefly explain. • 2. How is sexual reproduction different from asexual reproduction. • 3. Disadvantages of asexual reproduction? • 4. Place the phases of the cell cycle and mitosis in the correct order and give the name of the phase.

  23. Warmup March 15th #32 • Diploid and haploid • Somatic (body) cells are diploid, meaning that they have pairs of chromosomes. When a cell undergoes meiosis to prepare for sexual reproduction, the chromosome number must be reduced by half, creating a haploid cell. Homologous Chromosomes Each species has a specific number of chromosomes. Humans have 46 chromosomes in 23 homologous pairs. Each homologous pair has one chromosome from the mother and one from the father. Homologous chromosomes code for same traits.

  24. Sexual reproduction • Sexual:two sources of genetic material, makes four haploid sex cells (gametes) • Gametes: sperm and egg • Advantages: genetic variation, • Disadvantages: requires more time for mating, risk of unfavorable genetic combinations Fertilization

  25. Meiosis:Requires 2 divisions: Phases the same as Mitosis • Meiosis II • (2nd division): Reduces the genetic material • Result: 4 genetically different haploid cells- these cells are GAMETES (sex cells- egg and sperm) • Meiosis I (1st division): • Reduces the chromosome number; • Result: 2 genetically different daughter cells • (1n) 23 chromsomes but are still doubled) Meiosis Animation

  26. The entire process of Meiosis

  27. Meiosis allows for lots of variation (differences) • Variation as a result of: • Crossing Over: a part of one chromosome can switch places with the same part another homologous chromosome . • Random Assortment: of chromosomes allows a mix of chromosomes from both parents • Random Fertilization : of any egg by any sperm allows for lots of variation

  28. Meiosis Summary • Include the following words in a summary: • Meiosis, • sexual reproduction • homologous chromosomes • diploid parent cell • haploid daughter cells • 4 gametes • crossing-over • genetic recombination • Variation

  29. Ticket Out the Door Word Bank Traits Asexual Sexual Two Four Diploid Mitosis Crossing over Interphase Haploid • The number of cells produced as a result of meiosis is ________. • Homologous chromosomes code for same ________. • Meiosis is used for _________ reproduction. • The process that allows for genetic variation is called _________ during meiosis. • During meiosis the chromosome number must be reduced by half, creating a ________ cell

  30. Meiosis Square Dance • http://www.youtube.com/watch?v=iCL6d0OwKt8&feature=related

  31. Warm-up March 16th #33 • Nondisjunction • When homologous chromosomes do not separate during meiosis resulting in cells with too many or too few chromosomes. • Crossing-Over • When homologous chromosomes pair up during prophase I of meiosis a part of one chromosome switches places with the other. Since they are coding for the same traits this process produces more variation in the offspring.

  32. Problems with Meiosis: • Mutations: changes in the DNA before meiosis or mitosis begins • Nondisjunction: homologous chromosomes do not separate resulting in one too many or one too few chromosomes • Ex. Down syndrome : trisomy 21 • Nondisjunction Animation Karyotype- a picture of the chromosomes

  33. Nondisjunction

  34. Comparison of mitosis and Meiosis

  35. Ticket out the door • 1. How many cells are produced as a result of Meiosis? • 2. If a parent cell has 4 chromosomes and goes through MEIOSIS, how many chromosomes would the daughter cells contain? • 3. Meiosis is used for (sexual or asexual) reproduction? • 4. EXPLAIN the process of crossing-over.

  36. Warm-up • Take out pg. 92 and complete the mitosis and meiosis comparison chart • Get out case study • Get out problem solving

  37. Warm-up oct.4 #27 • Draw and label the following pictures. Identify and label cells as haploid OR diploid.

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