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Cell Division

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The document summarizes cell division and the cell cycle. It describes the key stages and phases of mitosis and meiosis. Mitosis produces two identical daughter cells through prophase, metaphase, anaphase and telophase. Meiosis produces four unique haploid daughter cells through two rounds of division and involves genetic shuffling through crossing over and independent assortment. The cell cycle and both mitosis and meiosis are essential for asexual and sexual reproduction.

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Cell Division Mitosis & Meiosis From the Virtual Cell Biology Classroom on ScienceProfOnline.comImage: Cell Division, Wikipedia
Eukaryotic Cell Cycle – Cell grows. – DNA is replicated. - Mitotic cell division produces daughter cell identical to the parent. Image: Cell cycle by Richard Wheeler From the Virtual Cell Biology Classroom on ScienceProfOnline.com Different from prokaryotic cell cycle, in that… – Eukaryotic cells have more DNA on many linear chromosomes. (Q: How many do humans have?). – The timing of replication and cell division is highly regulated. Like prokaryotic cell cycle, in that…
Eukaryotic Cell Cycle 2 major phases: • __________ (3 stages) – DNA uncondensed • ________ (4 stages + cytokinesis) - Nuclear division & division of cytoplasm – DNA condensed Image: Cell cycle by Richard Wheeler From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Interphase Non-dividing state With 3 sub-stages: ___ – cell grows in size – organelles replicated ___ – replication of DNA – synthesis of proteins associated with DNA ___ – synthesis of proteins associated with mitosis Image: Cell cycle by Richard Wheeler; Interphase in Onion Cell Drawing & Photo, Source Unknown From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Division of somatic cells (non-reproductive cells) in eukaryotic organisms. A single cell divides into two identical daughter cells. Daughter cells have same # of chromosomes as does parent cell. Mitosis From the Virtual Cell Biology Classroom on ScienceProfOnline.com Images: Cell cycle by Richard Wheeler; Overview of Mitosis, Mysid
Packing for the move… When cell is not dividing… ● DNA molecules in extended, uncondensed form = chromatin ● Cell can only replicate and transcribe DNA when in extended state. When cell is preparing for division… ● DNA molecules condense to form chromosomes prior to division. – each chromosome is a single molecule of DNA – easier to sort and organize the replicated DNA into daughter cells From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Mitosis 4 sub-phases: 1st – Prophase 2nd – Metaphase 3rd – Anaphase 4th – Telophase followed by Cytokinesis Secret to remembering phases in order… From the Virtual Cell Biology Classroom on ScienceProfOnline.comImage: Mitosis diagram, Marek Kultys
1. Prophase Images: Prophase drawing, Henry Gray's Anatomy of the Human Body; Prophase Onion Cell Drawing & Photo, Source Unknown, Fluoresced cell, National Institutes of Health 3 Major Events - chromosomes condense - spindle fibers form (spindle fibers are specialized microtubules radiating out from centrioles) - chromosomes are captured by spindle From the Virtual Cell Biology Classroom on ScienceProfOnline.com Fluoresced eukaryotic cell. Chromosomes in blue. Mitotic spindle apparatus in green.
chromatin nucleolus nucleus centrioles condensing chromosomes Prophase
• chromosomes align along equator of the cell, with one kinetochore facing each pole centrioles spindle fibers chromosomes 2. Metaphase Images: Metaphase drawing, Henry Gray's Anatomy of the Human Body; Metaphase Onion Cell Drawing & Photo, Source Unknown Kinetocores not pictured in this illustration.
3. Anaphase • sister chromatids separate • spindle fibers attached to kinetochores shorten and pull chromatids towards the poles. • free spindle fibers lengthen and push poles of cell apart Images: Anaphase drawing, Henry Gray's Anatomy of the Human Body; Anaphase Onion Cell Drawing & Photo, Source Unknown From the Virtual Cell Biology Classroom on ScienceProfOnline.com
4. Telophase • spindle fibers disintegrate • nuclear envelopes form around both groups of chromosomes •chromosomes revert to their extended state • cytokinesis occurs, enclosing each daughter nucleus into a separate cell Images: Telophase drawing, Henry Gray's Anatomy of the Human Body; Telophase Onion Cell Drawing & Photo, Source Unknown From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Cytokinesis – Plant vs. Animal Cell • Plant cells undergo cytokinesis by forming a cell plate between the two daughter nuclei. • Animal cells undergo cytokinesis through the formation of a cleavage furrow. A ring of microtubules contract, pinching the cell in half. From the Virtual Cell Biology Classroom on ScienceProfOnline.com Images: Telophase drawing, Henry Gray's Anatomy of the Human Body; Ciliate dividing, TheAlphaWolf; Telophase Onion Cell Photo, Source Unknown
Stages of Mitosis Image: Onion Cell Drawing & Photo, Source Unknown REVIEW! Mitosis Animations 1.Mitosis & Cytokinesis from McGraw-Hill 2.Mitosis Interactive Animation from Cells Alive
1. somatic cells 2. sex cells (a.k.a. gametes) SEXually reproducing eukaryotes, have 2 types of body cells… Image: Superficial human anatomy, Mikael Häggström& Rainer Zenz; Sperm & egg, Wikipedia Made you look! Genetics Terminology From the Virtual Cell Biology Classroom on ScienceProfOnline.com
- A single germ cell divides into four unique daughter cells. - Daughter cells have half the # of chromosomes as parent cell, so they considered haploid. Image: Overview of Meiosis, National Institutes of Health What is cell division of gametes called? Meiosis From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Diploid organisms receive one of each type of chromosome from female parent (maternal chromosomes) and one of each type of chromosome from male parent (paternal chromosomes) Refers to the number of sets of chromosomes in cells. ● Haploid – one copy of each chromosome – designated as “n”, the number of chromosomes in one “set” - gametes ● Diploid – two sets of chromosomes - two of each chromosome – designated as “2n” - somatic cells Genetics Terminology: Ploidy From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Genetics Terminology: Homologues Chromosomes exist in homologous pairs in diploid (2n) cells. Exception: Sex chromosomes (X, Y). Other chromosomes, known as autosomes, they have homologues. From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Karyotype • Q: Which, of the top two karyotypes is replicated? • Q: How many homologous pair in each karyotype? • Q: How is the bottom karyotype different from the top two? Image: Karyotype, National Human Genome Research InstituteFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
Asexual Reproduction – Many single-celled organisms reproduce by splitting, budding. – Some multicellular organisms can reproduce asexually, produce clones (offspring genetically identical to parent). – Q: What type of cell division is asexual reproduction? Image: Paatrick Star, Nickelodeon; Hydra budding, Lifetrance;From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Sexual Reproduction • Fusion of two gametes to produce a single zygote. • Introduces greater genetic variation, allows genetic recombination. • With exception of self- fertilizing organisms, zygote has gametes from two different parents. Peter + Lois = Stewie Images: Peter, Lois & Stewie, The Family Guy From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Sexual reproduction in humans … • At fertilization, 23 chromosomes are donated by each parent. (total = 46 or 23 pairs). • Gametes (sperm/ova): – Contain 22 autosomes and 1 sex chromosome. – Are haploid (haploid number “n” = 23 in humans). • Fertilization results in diploid zygote. – Diploid cell; 2n = 46. (n = 23 in humans) • Q: Most cells in the body are produced through what type of cell division? • Only gametes are produced through meiosis. Image: Superficial human anatomy, Mikael Häggström& Rainer Zenz; Sperm & egg, Wikipedia From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Meiosis - Sex Cell (Gamete) Formation In meiosis, there are 2 divisions of the nucleus: meiosis I & meiosis II Image: Overview of Meiosis, National Institutes of Health From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Image: Meiosis diagram, Marek KultysFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com REVIEW! Meiosis Animations 1.How Meiosis Works from McGraw-Hill 2.Meiosis Interactive Animation from Cells Alive
Meiosis & Sexual Reproduction Life Cycle Image: Animal Life Cycle, Dr. T’s Bio 328 Genetics Mitosis * * * From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Genetic Variation in Diploid Organisms • Fusion of sperm and egg results in unique offspring. • But not only because the young are a product of two individuals with different genetic makeup. • Meiosis “shuffles” the genes so that the an individual’s gametes are genetically different from one another. From the Virtual Cell Biology Classroom on ScienceProfOnline.com Image: Meiosis diagram, Marek Kultys How is this shuffling accomplished?
Genetic shuffling of Meiosis I In addition to a new combination of chromosomes resulting from fertilization, there are also events in Meiosis I that shuffle the genes. 1. Crossing over in Prophase I. 2. Independent assortment in Metaphase I. From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Crossing Over • Homologues break at identical locations, then rejoin opposite partners. • This creates new combinations of the alleles on each chromosome. • Occurs randomly several times on every chromosome. • Results in mixing of the genes you inherited from your parents. Image: Meiosis diagram, Marek Kultys ; Crossing over, Thomas Hunt Morgan, Molecular crossing over, David HallFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
Independent Assortment REVIEW! Independent Assortment Animations 1.Independent Assortment from Sinauer Associates 2.Random Orientation of Chromosomes During Meiosis from McGraw-Hill
Spermatogenesis Image: Spermatogenesis, WikiFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com Males produce sperm throughout life, after the onset of puberty, about 1,500 sperm per second.
Oogenesis Image: Oogenesis, WikiFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com Oogenesis in females is probably complete either before or shortly after birth. During oogenesis, three polar bodies develop as the mature ovum is generated. Polar bodies contain little cytoplasm and eventually degenerate.
Mitosis vs. Meiosis • 2n • Clone • Same genetic information in parent cell and daughter cell. • Give me another one just like the other one! • 1n • Daughter cells different from parent cell and from each other. • Daughter cells have ½ the number of chromosomes as somatic cell. • Shuffling the genes (Mix it up!) • See animation “ Unique Features of Meiosis” from McGraw-Hill From the Virtual Cell Biology Classroom on ScienceProfOnline.com REVIEW! Animations Comparing Mitosis & Meiosis Quiz 1 and Quiz 2 from McGraw-Hill
Image: Mitosis diagram & Meiosis diagram, Marek Kultys From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Drawing and Labeling Chromosomes Sister Chromatid Replicated Uncondensed Chromosome (chromatin) Sister Chromatid Centromere Unreplicated Uncondensed Chromosome (chromatin) From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Drawing & Labeling Homologous Chromosomes Unreplicated, Condensed, Homologous Chromosomes Replicated, Condensed, Homologous Chromosomes From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Meiosis Demo & Practice • Break up into groups & get kit. • Each kit should have: - 6 duplicated chromosomes (3 sets of homologues). - 4 pieces of string - plastic centromere pieces • Use chromosome kits to work through the stages of meiosis. • BEFORE you start writing on your Meiosis Worksheet, make sure that you have modeled the stages of Meiosis with the chromosome kits. (If your group needs help, raise your hand & I will come over assist.) • Do not depict cross-over in your diagrams. You need to be able to track the journey of each individual chromosome from start to finish. See the ScienceProfOnline Virtual Cell Biology Classroom Genetics: Cell Division - Meiosis & Sexual Reproduction for a printable Word .doc of this assignment. From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Confused? Here are links to fun resources that further explain meiosis: • Meiosis Main Page on the Virtual Cell Biology Classroom of Science Prof Online. • “Meiosis: Where the Sex Starts”, video from Crash Course Biology • Meiosis animation, step-through and quiz, Sadava, et al., Life: The Science of Biology, 9th Edition, Sinauer Associates. • Meiosis step through animation from CellsAlive.com. • “X & Y” song by Coldplay • Meiosis animation from McGraw-Hill. • Independent Assortment animation from Sinauer Associates. • “Let’s Talk About Sex” music video by Salt ‘n’ Pepa. From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Are you feeling blinded by science? Do yourself a favor. Use the… Virtual Cell Biology Classroom (VCBC) ! The VCBC is full of resources to help you succeed, including:• practice test questions • review questions • study guides and learning objectives • PowerPoints on other topics You can access the Virtual Cell Biology Classroom (VCBC) on the Science Prof Online website www.ScienceProfOnline.com Images: Blinded With Science album, Thomas Dolby; Endomembrane system, Mariana Ruiz, Wiki

More Related Content

Cell Division

  • 1. Cell Division Mitosis & Meiosis From the Virtual Cell Biology Classroom on ScienceProfOnline.comImage: Cell Division, Wikipedia
  • 2. Eukaryotic Cell Cycle – Cell grows. – DNA is replicated. - Mitotic cell division produces daughter cell identical to the parent. Image: Cell cycle by Richard Wheeler From the Virtual Cell Biology Classroom on ScienceProfOnline.com Different from prokaryotic cell cycle, in that… – Eukaryotic cells have more DNA on many linear chromosomes. (Q: How many do humans have?). – The timing of replication and cell division is highly regulated. Like prokaryotic cell cycle, in that…
  • 3. Eukaryotic Cell Cycle 2 major phases: • __________ (3 stages) – DNA uncondensed • ________ (4 stages + cytokinesis) - Nuclear division & division of cytoplasm – DNA condensed Image: Cell cycle by Richard Wheeler From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 4. Interphase Non-dividing state With 3 sub-stages: ___ – cell grows in size – organelles replicated ___ – replication of DNA – synthesis of proteins associated with DNA ___ – synthesis of proteins associated with mitosis Image: Cell cycle by Richard Wheeler; Interphase in Onion Cell Drawing & Photo, Source Unknown From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 5. Division of somatic cells (non-reproductive cells) in eukaryotic organisms. A single cell divides into two identical daughter cells. Daughter cells have same # of chromosomes as does parent cell. Mitosis From the Virtual Cell Biology Classroom on ScienceProfOnline.com Images: Cell cycle by Richard Wheeler; Overview of Mitosis, Mysid
  • 6. Packing for the move… When cell is not dividing… ● DNA molecules in extended, uncondensed form = chromatin ● Cell can only replicate and transcribe DNA when in extended state. When cell is preparing for division… ● DNA molecules condense to form chromosomes prior to division. – each chromosome is a single molecule of DNA – easier to sort and organize the replicated DNA into daughter cells From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 7. Mitosis 4 sub-phases: 1st – Prophase 2nd – Metaphase 3rd – Anaphase 4th – Telophase followed by Cytokinesis Secret to remembering phases in order… From the Virtual Cell Biology Classroom on ScienceProfOnline.comImage: Mitosis diagram, Marek Kultys
  • 8. 1. Prophase Images: Prophase drawing, Henry Gray's Anatomy of the Human Body; Prophase Onion Cell Drawing & Photo, Source Unknown, Fluoresced cell, National Institutes of Health 3 Major Events - chromosomes condense - spindle fibers form (spindle fibers are specialized microtubules radiating out from centrioles) - chromosomes are captured by spindle From the Virtual Cell Biology Classroom on ScienceProfOnline.com Fluoresced eukaryotic cell. Chromosomes in blue. Mitotic spindle apparatus in green.
  • 10. • chromosomes align along equator of the cell, with one kinetochore facing each pole centrioles spindle fibers chromosomes 2. Metaphase Images: Metaphase drawing, Henry Gray's Anatomy of the Human Body; Metaphase Onion Cell Drawing & Photo, Source Unknown Kinetocores not pictured in this illustration.
  • 11. 3. Anaphase • sister chromatids separate • spindle fibers attached to kinetochores shorten and pull chromatids towards the poles. • free spindle fibers lengthen and push poles of cell apart Images: Anaphase drawing, Henry Gray's Anatomy of the Human Body; Anaphase Onion Cell Drawing & Photo, Source Unknown From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 12. 4. Telophase • spindle fibers disintegrate • nuclear envelopes form around both groups of chromosomes •chromosomes revert to their extended state • cytokinesis occurs, enclosing each daughter nucleus into a separate cell Images: Telophase drawing, Henry Gray's Anatomy of the Human Body; Telophase Onion Cell Drawing & Photo, Source Unknown From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 13. Cytokinesis – Plant vs. Animal Cell • Plant cells undergo cytokinesis by forming a cell plate between the two daughter nuclei. • Animal cells undergo cytokinesis through the formation of a cleavage furrow. A ring of microtubules contract, pinching the cell in half. From the Virtual Cell Biology Classroom on ScienceProfOnline.com Images: Telophase drawing, Henry Gray's Anatomy of the Human Body; Ciliate dividing, TheAlphaWolf; Telophase Onion Cell Photo, Source Unknown
  • 14. Stages of Mitosis Image: Onion Cell Drawing & Photo, Source Unknown REVIEW! Mitosis Animations 1.Mitosis & Cytokinesis from McGraw-Hill 2.Mitosis Interactive Animation from Cells Alive
  • 15. 1. somatic cells 2. sex cells (a.k.a. gametes) SEXually reproducing eukaryotes, have 2 types of body cells… Image: Superficial human anatomy, Mikael Häggström& Rainer Zenz; Sperm & egg, Wikipedia Made you look! Genetics Terminology From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 16. - A single germ cell divides into four unique daughter cells. - Daughter cells have half the # of chromosomes as parent cell, so they considered haploid. Image: Overview of Meiosis, National Institutes of Health What is cell division of gametes called? Meiosis From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 17. Diploid organisms receive one of each type of chromosome from female parent (maternal chromosomes) and one of each type of chromosome from male parent (paternal chromosomes) Refers to the number of sets of chromosomes in cells. ● Haploid – one copy of each chromosome – designated as “n”, the number of chromosomes in one “set” - gametes ● Diploid – two sets of chromosomes - two of each chromosome – designated as “2n” - somatic cells Genetics Terminology: Ploidy From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 18. Genetics Terminology: Homologues Chromosomes exist in homologous pairs in diploid (2n) cells. Exception: Sex chromosomes (X, Y). Other chromosomes, known as autosomes, they have homologues. From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 19. Karyotype • Q: Which, of the top two karyotypes is replicated? • Q: How many homologous pair in each karyotype? • Q: How is the bottom karyotype different from the top two? Image: Karyotype, National Human Genome Research InstituteFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 20. Asexual Reproduction – Many single-celled organisms reproduce by splitting, budding. – Some multicellular organisms can reproduce asexually, produce clones (offspring genetically identical to parent). – Q: What type of cell division is asexual reproduction? Image: Paatrick Star, Nickelodeon; Hydra budding, Lifetrance;From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 21. Sexual Reproduction • Fusion of two gametes to produce a single zygote. • Introduces greater genetic variation, allows genetic recombination. • With exception of self- fertilizing organisms, zygote has gametes from two different parents. Peter + Lois = Stewie Images: Peter, Lois & Stewie, The Family Guy From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 22. Sexual reproduction in humans … • At fertilization, 23 chromosomes are donated by each parent. (total = 46 or 23 pairs). • Gametes (sperm/ova): – Contain 22 autosomes and 1 sex chromosome. – Are haploid (haploid number “n” = 23 in humans). • Fertilization results in diploid zygote. – Diploid cell; 2n = 46. (n = 23 in humans) • Q: Most cells in the body are produced through what type of cell division? • Only gametes are produced through meiosis. Image: Superficial human anatomy, Mikael Häggström& Rainer Zenz; Sperm & egg, Wikipedia From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 23. Meiosis - Sex Cell (Gamete) Formation In meiosis, there are 2 divisions of the nucleus: meiosis I & meiosis II Image: Overview of Meiosis, National Institutes of Health From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 24. Image: Meiosis diagram, Marek KultysFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com REVIEW! Meiosis Animations 1.How Meiosis Works from McGraw-Hill 2.Meiosis Interactive Animation from Cells Alive
  • 25. Meiosis & Sexual Reproduction Life Cycle Image: Animal Life Cycle, Dr. T’s Bio 328 Genetics Mitosis * * * From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 26. Genetic Variation in Diploid Organisms • Fusion of sperm and egg results in unique offspring. • But not only because the young are a product of two individuals with different genetic makeup. • Meiosis “shuffles” the genes so that the an individual’s gametes are genetically different from one another. From the Virtual Cell Biology Classroom on ScienceProfOnline.com Image: Meiosis diagram, Marek Kultys How is this shuffling accomplished?
  • 27. Genetic shuffling of Meiosis I In addition to a new combination of chromosomes resulting from fertilization, there are also events in Meiosis I that shuffle the genes. 1. Crossing over in Prophase I. 2. Independent assortment in Metaphase I. From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 28. Crossing Over • Homologues break at identical locations, then rejoin opposite partners. • This creates new combinations of the alleles on each chromosome. • Occurs randomly several times on every chromosome. • Results in mixing of the genes you inherited from your parents. Image: Meiosis diagram, Marek Kultys ; Crossing over, Thomas Hunt Morgan, Molecular crossing over, David HallFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 29. Independent Assortment REVIEW! Independent Assortment Animations 1.Independent Assortment from Sinauer Associates 2.Random Orientation of Chromosomes During Meiosis from McGraw-Hill
  • 30. Spermatogenesis Image: Spermatogenesis, WikiFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com Males produce sperm throughout life, after the onset of puberty, about 1,500 sperm per second.
  • 31. Oogenesis Image: Oogenesis, WikiFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com Oogenesis in females is probably complete either before or shortly after birth. During oogenesis, three polar bodies develop as the mature ovum is generated. Polar bodies contain little cytoplasm and eventually degenerate.
  • 32. Mitosis vs. Meiosis • 2n • Clone • Same genetic information in parent cell and daughter cell. • Give me another one just like the other one! • 1n • Daughter cells different from parent cell and from each other. • Daughter cells have ½ the number of chromosomes as somatic cell. • Shuffling the genes (Mix it up!) • See animation “ Unique Features of Meiosis” from McGraw-Hill From the Virtual Cell Biology Classroom on ScienceProfOnline.com REVIEW! Animations Comparing Mitosis & Meiosis Quiz 1 and Quiz 2 from McGraw-Hill
  • 33. Image: Mitosis diagram & Meiosis diagram, Marek Kultys From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 34. Drawing and Labeling Chromosomes Sister Chromatid Replicated Uncondensed Chromosome (chromatin) Sister Chromatid Centromere Unreplicated Uncondensed Chromosome (chromatin) From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 35. Drawing & Labeling Homologous Chromosomes Unreplicated, Condensed, Homologous Chromosomes Replicated, Condensed, Homologous Chromosomes From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 36. Meiosis Demo & Practice • Break up into groups & get kit. • Each kit should have: - 6 duplicated chromosomes (3 sets of homologues). - 4 pieces of string - plastic centromere pieces • Use chromosome kits to work through the stages of meiosis. • BEFORE you start writing on your Meiosis Worksheet, make sure that you have modeled the stages of Meiosis with the chromosome kits. (If your group needs help, raise your hand & I will come over assist.) • Do not depict cross-over in your diagrams. You need to be able to track the journey of each individual chromosome from start to finish. See the ScienceProfOnline Virtual Cell Biology Classroom Genetics: Cell Division - Meiosis & Sexual Reproduction for a printable Word .doc of this assignment. From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 37. Confused? Here are links to fun resources that further explain meiosis: • Meiosis Main Page on the Virtual Cell Biology Classroom of Science Prof Online. • “Meiosis: Where the Sex Starts”, video from Crash Course Biology • Meiosis animation, step-through and quiz, Sadava, et al., Life: The Science of Biology, 9th Edition, Sinauer Associates. • Meiosis step through animation from CellsAlive.com. • “X & Y” song by Coldplay • Meiosis animation from McGraw-Hill. • Independent Assortment animation from Sinauer Associates. • “Let’s Talk About Sex” music video by Salt ‘n’ Pepa. From the Virtual Cell Biology Classroom on ScienceProfOnline.com
  • 38. Are you feeling blinded by science? Do yourself a favor. Use the… Virtual Cell Biology Classroom (VCBC) ! The VCBC is full of resources to help you succeed, including:• practice test questions • review questions • study guides and learning objectives • PowerPoints on other topics You can access the Virtual Cell Biology Classroom (VCBC) on the Science Prof Online website www.ScienceProfOnline.com Images: Blinded With Science album, Thomas Dolby; Endomembrane system, Mariana Ruiz, Wiki

Editor's Notes

  1. Interphase Cell Division
  2. G1 S G2
  3. I Peed on the MAT.