Presentation dna grade 10


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Grade 10 Life and Living DNA

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Presentation dna grade 10

  1. 1. Inheritance and change: dna¤ characteristics and inheritance<br />Grade 10 / 2011 life and living<br />BIOLOGY<br />Compiled by:<br />Madre’ Nortje<br />
  2. 2. A Brief Introduction to Genetics<br />22/05/2011<br />Science grade 10/DNA<br />2<br />A Brief Introduction to Genetics is a short documentary film created using motion graphics as the main visual component. It is a film that explores the history of genetics & genomics and the... 823 views since Aug 15, 2010submitted by: dmetzky<br />ASSIGNMENT GOOD WEB PAGE:<br />
  3. 3. A Brief Introduction to Genetics<br />22/05/2011<br />Science grade 10/DNA<br />3<br /><br />
  4. 4. Characteristics and inheritance<br />22/05/2011<br />Science grade 10/DNA<br />4<br />HOMOLOGOUS<br /><ul><li>An organ that is similar to another in: structure, function, position and development.</li></li></ul><li>HOMOLOGOUS<br /><ul><li>After the fusion of the egg and sperm the chromosomes in the zygote now exist as 23 pairs. 23 from each sex cell.
  5. 5. Homologous chromosomes exist as they have the same genes for particular characteristics at the same location on the chromosomes.
  6. 6. The zygote has two genes for each characteristic – one from each parent.</li></ul>Science grade 10/DNA<br />22/05/2011<br />5<br />
  7. 7. Gregor mendel 1822 -1884“Father of genetics”<br /><br />Science grade 10/DNA<br />22/05/2011<br />6<br />
  8. 8. Mendel Pea Theory<br />22/05/2011<br />Science grade 10/DNA<br />7<br /><br /><ul><li>Pure breeding means that parents produce offspring off same colour only.</li></li></ul><li>Mendel Pea Theory<br />22/05/2011<br />Science grade 10/DNA<br />8<br /><br />
  9. 9. GENETIC PEAS<br />22/05/2011<br />Science grade 10/DNA<br />9<br />Gene controlling the colour <br />Pea plants with the alternate alleles<br />CG dark green – incompletely dominant <br />CY yellow – defective chlorophyll<br /> – unable to photosynthesize – die<br />youngGenetic‑Coding.gif<br />200 × 349 - ... insight into the DNA of the pea, by unravelling its genetic coding.<br /><br /><br />
  10. 10. GENETIC PEAS TYPE<br />22/05/2011<br />Science grade 10/DNA<br />10<br /><ul><li>GENOTYPE PHENOTYPE
  11. 11. CG CG Dark green
  12. 12. CG CY Light green
  13. 13. CY CY Yellow
  14. 14. Plants grown from Genotype CGCY X CGCY
  15. 15. Pea plants are self fertilizing – cross giving rise to Genotype seed</li></ul>CG CG : 2CG CY : CY CY <br />
  16. 16. GENETIC BARLEY<br />22/05/2011<br />Science grade 10/DNA<br />11<br /><br />Gene controlling pigment<br />Producing the alternate alleles<br />A: Pigment produced – green (dominant)<br />‘a: No pigment – albino / or white (recessive)<br />
  17. 17. GENETIC BARLEY TYPE<br />22/05/2011<br />Science grade 10/DNA<br />12<br /> <br />Plants grown from Genotype Aa x Aa<br />Germinated seeds, can grow into<br />AA – green<br />Aa – green<br />Aa – albino / white<br /> <br />Plants obtained ratio – <br />3 green: 1 white<br />
  18. 18. Characteristics and inheritanceDOMINANT AND Recessive genes<br /><ul><li>PEDIGREE PURE BREEDING:
  19. 19. Family trees, showing the inheritance of particular characteristics from one generation to later generations.
  21. 21. A gene for a particular characteristic that completely hides or masks the alternative (recessive) gene.</li></ul>22/05/2011<br />Science grade 10/DNA<br />13<br />
  22. 22. Characteristics and inheritanceDOMINANT AND Recessive genes<br /><ul><li>RECESSIVE GENE
  23. 23. A gene for a particular characteristic that is completely hidden or masked by the alternative (dominant) gene
  25. 25. Alleles (a-LEELs): different forms of the same gene; each allele produces variations in inherited characteristics, e.g. eye colour</li></ul>22/05/2011<br />Science grade 10/DNA<br />14<br />
  26. 26. <ul><li>HOMOZYGOUS
  27. 27. Homozygous (HO-mo-ZYE-gus): where the genes for particular characteristic are the same; a pure breeder
  29. 29. Heterozygous (HET-er-o-ZYE-gus): where the genes for a particular characteristic are different; a hybrid</li></ul>22/05/2011<br />Science grade 10/DNA<br />15<br />Characteristics and inheritanceDOMINANT AND Recessive genes<br />
  30. 30. Dominant and recessive genes<br /><ul><li>The RR and rr combinations of alleles where the offspring is identical to parent are HOMOZYGOUS
  31. 31. The Rr combinations of alleles is known as HETEROZYGOUS.</li></ul>Science grade 10/DNA<br />22/05/2011<br />16<br />
  32. 32. Science grade 10/DNA<br />22/05/2011<br />17<br />
  34. 34. Genotype (JEE-no-type): the type of genes possess in an organism (BB, BW and WW) for specific characteristic (pg. 131 – Black, White or Blue – grey feathers)
  35. 35. PHENOTYPE
  36. 36. Phenotype (FEE-no-type): the physical appearance or characteristics of an organism (pg. 131 – the colour Black, White or Blue – grey)</li></li></ul><li>.<br />INCOMPLETE DOMINANCE<br />some genes do not have dominant or recessive alleles and results in a heterozygous individual (blended)<br />e.g. black-feathered (BB) and white-feathered (WW) chickens mating to create a blue/grey-feathered (BW) offspring<br />The terms BB, WW and BW are called genotypes.<br />The physical characteristic (feather colour) is called the phenotype<br />22/05/2011<br />Science grade 10/DNA<br />19<br />Other patterns….Not all genes are inherited as simple recessive or dominant genes<br />
  37. 37. OTHER Patterns OF INHERITANCE<br />22/05/2011<br />Science grade 10/DNA<br />20<br />THREE FORMS continue:<br />2. CO – DOMINANCE<br /><ul><li>BOTH OFFSPRING ARE EXPRESSED IN THE PHENOTYPE – e.g. Blood groups</li></li></ul><li>Co – dominance ON HAND OF BLOOD TYPE<br />Some cases have both alleles in the heterozygous offspring expressed in the phenotype<br />E.g. – blood type<br />Three alleles for blood type gene and the types A, B, O and AB exist<br />AB can form both A or B and has characteristics of both A and B but is not a blend<br />A and B are dominant to O thus O will only occur in OO homozygous individual<br />22/05/2011<br />Science grade 10/DNA<br />21<br />
  38. 38. OTHER PATTERS OF INHERITANCE<br />22/05/2011<br />Science grade 10/DNA<br />22<br />THREE FORMS continue:<br />3. SEX – LINKING / SEX DETERMINATION<br /><ul><li>Chromosomes: objects found in the nucleus of a cell that carry the genetic information
  40. 40. XX - female
  41. 41. XY - male
  42. 42. AUTOSOMES
  43. 43. All other chromosomes are referred to as autosomes</li></li></ul><li>Sex Determination<br />X and Y chromosomes <br />The only two chromosomes that determine what sex you will be<br />All other chromosomes are referred to as autosomes<br />XX - female<br />XY - male<br />The X and Y chromosomes <br />22/05/2011<br />Science grade 10/DNA<br />23<br />X & Y<br />♀<br />♂<br />
  44. 44. ALLELE FOR COLOUR-BLINDNESS: <br />22/05/2011<br />Science grade 10/DNA<br />24<br />X CHROMOSOME<br />
  45. 45. DIFFERENCE<br />♀ FEMALE<br /><ul><li>Eggs will have 23 chromosomes one of which will be X</li></ul>♂ MALE<br /><ul><li>Sperm will have 23 chromosomes, but half of the sperm carry X chromosome and the other half carry Y chromosome</li></ul>22/05/2011<br />Science grade 10/DNA<br />25<br />
  46. 46. FERTILISATION: ♂ MALE ->♀<br />If a male sperm….<br />Containing X fertilizes an egg  female (XX)<br />Containing Y fertilises and egg  male (XY)<br />22/05/2011<br />Science grade 10/DNA<br />26<br />
  47. 47. Sex linkage<br />Sex-linked genes - found on X chromosome and not on Y and vice versa.<br />E.g.:<br />Colour blindness<br />Haemophilia<br />Duchenne’s muscular dystrophy<br />22/05/2011<br />Science grade 10/DNA<br />27<br />
  48. 48. 22/05/2011<br />Science grade 10/DNA<br />28<br />
  50. 50. Permanent changes in genes, they may be caused by exposure to a ->
  51. 51. MUTAGEN
  52. 52. Something that causes a mutation
  54. 54. UV radiation
  55. 55. X – Ray
  56. 56. Agricultural and Industrial Chemicals</li></ul>22/05/2011<br />Science grade 10/DNA<br />29<br />
  57. 57. HANDOUTS TO be COMPLETE – Hand back on TUESDAY NEXT WEEK<br />1.Questions: How to find Your Learning Style<br />2. Online Questionnaire on Learning Styles<br /><br />3. How to make your own DNA Code Bracelet<br />22/05/2011<br />Science grade 10/DNA<br />30<br />
  58. 58. Great news! <br />You all NOW have the GREAT Opportunity to learn more about genetic disorders <br />YOUR BIOLOGY <br />Assignment!!!!<br />Test what you know?<br />Questions 2.2 p 135<br />Science grade 10/DNA<br />22/05/2011<br />31<br />HOMEWORK: QUESTIONS 2.2 - P135<br />
  59. 59. NATURAL SELECTION<br />Selection of certain characteristics for survival in nature<br />Organisms possess structural, functional and behavioural characteristics that enable them to survive in their environments <br />Those that do not are less likely to survive and thus less likely to reproduce and not pass on those weaknesses<br />Science grade 10/DNA<br />22/05/2011<br />32<br />
  60. 60. Just means change.<br />Also the name given to the process whereby new life forms develop<br />Influenced by such things as physical barriers (mountains, rivers, oceans) known as geographic isolation<br />EVOLUTION<br />Science grade 10/DNA<br />22/05/2011<br />33<br />
  61. 61. EVOLUTION<br />If a species is separated by such, they may develop different adaptation so much so that they can no longer interbreed<br />This is referred to as Speciation<br />Science grade 10/DNA<br />22/05/2011<br />34<br />EVOLUTION<br />
  62. 62. EVOLUTION<br />Best summarised in 5 points<br />Variation exists within any population of organisms<br />All organism face a daily struggle to survive and reproduce, whether to find mates, seek shelter/food, escape predators<br />Those that are best able to survive and reproduce will do so<br />Science grade 10/DNA<br />22/05/2011<br />35<br />
  63. 63. EVOLUTION<br />Those that reproduce pass on the advantageous characteristics to their offspring<br />Over time, the population will become better suited to its environment<br />The theory of evolution can explain how plants and animals have gradually changed into new, different kinds over long periods of time<br />Science grade 10/DNA<br />22/05/2011<br />36<br />
  64. 64. SUMMARY Questions<br />Science grade 10/DNA<br />22/05/2011<br />37<br />
  65. 65. But remember….<br /><ul><li>So what is the evidence for Evolution??</li></ul>If an environment changes too rapidly and the genes required for survival in the changed environment are not present in the gene pool….EXTINCTION may occur.<br />Science grade 10/DNA<br />22/05/2011<br />38<br />
  66. 66. FOSSIL EVIDENCE<br /><ul><li>Study of skeletal structure from fossils
  67. 67. Evidence of locations
  68. 68. Evidence of past environments</li></ul>Science grade 10/DNA<br />22/05/2011<br />39<br />
  69. 69. But remember…. Fossils.....<br /><ul><li>So what is the evidence for Evolution??</li></ul>Science grade 10/DNA<br />22/05/2011<br />40<br />
  70. 70. Comparative Embryology<br />Science grade 10/DNA<br />22/05/2011<br />41<br /><ul><li>In certain stages of development, embryos of organisms in the same group e.g. vertebrates, have similar structures</li></ul> (a) pig<br /> (b) cow<br /> (c) Rabbit<br /> (d) human<br />
  71. 71. Comparative anatomy<br />22/05/2011<br />Science grade 10/DNA<br />42<br />
  72. 72. DESIGN OF EXPERIMENT: Steps to follow - Clear and Simple p 20 Grade 8<br />22/05/2011<br />Science grade 10/DNA<br />43<br />
  73. 73. Revision: SCIENCE ALPHA TABLE(I)Date Updated: 18/05/2011<br />22/05/2011<br />Science grade 10/DNA<br />44<br />
  74. 74. Revision: SCIENCE ALPHA TABLE (II)Date Updated: 18/05/2011 <br />22/05/2011<br />Science grade 10/DNA<br />45<br />
  75. 75. Revision: SCIENCE ALPHA TABLE (III)Date Updated: 18/05/2011 <br />22/05/2011<br />Science grade 10/DNA<br />46<br />