Bio22 4th post lab discussion


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  • Amphioxus-cephalochordata
  • Tay-Sachs disease, it causes a relentless deterioration of mental and physical abilities that commences around six months of age and usually results in death by the age of four
  • Bio22 4th post lab discussion

    1. 1. 4th Post lab discussion<br />Bio22 LManahan<br />
    2. 2. Embryology<br />Development of embryo<br />Fertilization<br />Cleavage<br />Gastrulation<br />Neurulation<br />Organogenesis<br />
    3. 3. Fertilization<br /><ul><li>Fertilization membrane
    4. 4. Hardened vitelline membrane to prevent further sperm penetration
    5. 5. Perivitelline space
    6. 6. Grey crescent
    7. 7. Jelly coats</li></ul>It prevents too many sperm from getting to the egg at the same time, because of its viscosity.<br />Proteins in the jelly initiate the acrosome reaction in sperm so they are ready to fertilize the egg.<br />It provides a sort of "shock absorber" to prevent injury .<br />
    8. 8. Figure 32.1 Early es,mbryonic development (Layer 1)<br />Cleavage is a series of rapid mitotic divisions (without cell growth)<br />
    9. 9.
    10. 10. (d)<br />Blastula. A single layer of cells <br />surrounds a large blastocoel <br />cavity. Although not visible here, <br />the fertilization envelope is still <br />present; the embryo will soon <br />hatch from it and begin swimming.<br />Four-cell stage. Remnants of the <br />mitotic spindle can be seen <br />between the two cells that have <br />just completed the second <br />cleavage division.<br />(b)<br />Morula. After further cleavage <br />divisions, the embryo is a <br />multicellular ball that is still<br />surrounded by the fertilization <br />envelope. The blastocoel cavity<br />has begun to form.<br />(c)<br />Cleavage partitions the cytoplasm of one large cell<br />Into many smaller cells called blastomeres<br />Fertilized egg. Shown here is the<br />zygote shortly before the first <br />cleavage division, surrounded <br />by the fertilization envelope. <br />The nucleus is visible in the <br />center.<br />(a)<br />Figure 47.7a–d<br />
    11. 11. <ul><li>These cells are pluripotent (have the potential to become ANY of the 220 types of cells in the human body). These are embryonic stem cells
    12. 12. Which is holoblastic and which is meroblastic?</li></li></ul><li>The development of body axes in frogs<br />Is influenced by the polarity of the egg<br />Anterior<br />(a)<br />Body axes. The three axes of the fully developed embryo, the<br />tadpole, are shown above.<br />Right<br />Dorsal<br />Ventral<br />Left<br />Posterior<br />Animal<br />hemisphere<br />Animal pole<br />Point of<br />sperm entry<br />1<br />The polarity of the egg determines the anterior-posterior axis <br />before fertilization.<br />Vegetal<br />hemisphere<br />Vegetal pole<br />Point of<br />sperm<br />entry<br />At fertilization, the pigmented cortex slides over the underlying<br />cytoplasm toward the point of sperm entry. This rotation (red arrow)<br />exposes a region of lighter-colored cytoplasm, the gray crescent, <br />which is a marker of the dorsal side. <br />2<br />Future<br />dorsal<br />side of<br />tadpole<br />Gray<br />crescent<br />First<br />cleavage<br />3<br />The first cleavage division bisects the gray crescent. Once the anterior-<br />posterior and dorsal-ventral axes are defined, so is the left-right axis.<br />Figure 47.8a, b<br />(b) Establishing the axes. The polarity of the egg and cortical rotation are critical in setting up the body axes.<br />
    13. 13.
    14. 14.
    15. 15.
    16. 16. SURFACE VIEW<br />CROSS SECTION<br />Animal pole<br />1<br />Gastrulation begins when a small indented crease, <br />the dorsal lip of the blastopore, appears on one <br />side of the blastula. The crease is formed by cells<br />changing shape and pushing inward from the <br />surface (invagination). Additional cells then roll<br />inward over the dorsal lip (involution) and move into<br />the interior, where they will form endoderm and<br />mesoderm. Meanwhile, cells of the animal pole, the <br />future ectoderm, change shape and begin spreading <br />over the outer surface.<br />Blastocoel<br />Dorsal lip<br />of blastopore<br />Dorsal lip<br />of blastopore<br />Blastula<br />Vegetal pole<br />Archenteron<br />Blastocoel<br />shrinking<br />The blastopore lip grows on both sides of the <br />embryo, as more cells invaginate. When the sides <br />of the lip meet, the blastopore forms a circle that<br />becomes smaller as ectoderm spreads downward <br />over the surface. Internally, continued involution<br />expands the endoderm and mesoderm, and the <br />archenteron begins to form; as a result, the <br />blastocoel becomes smaller.<br />2<br />Ectoderm<br />3<br />Late in gastrulation, the endoderm-lined archenteron <br />has completely replaced the blastocoel and the <br />three germ layers are in place. The circular blastopore <br />surrounds a plug of yolk-filled cells.<br />Blastocoel<br />remnant<br />Mesoderm<br />Endoderm<br />Key<br />Future ectoderm<br />Future mesoderm<br />Figure 47.12<br />Yolk plug<br />Yolk plug<br />Gastrula<br />Future endoderm<br />The mechanics of gastrulation in a frog <br />
    17. 17.
    18. 18. Organogenesis<br />Various regions of the three embryonic germ layers<br />Develop into the rudiments of organs during the process of organogenesis<br />
    19. 19. Neurulation<br />Neural folds<br />LM<br />1 mm<br />Neural<br />fold<br />Neural<br />plate<br />Notochord<br />Ectoderm<br />Mesoderm<br />Endoderm<br />Archenteron<br />Neural plate formation. By the time<br />shown here, the notochord has <br />developed from dorsal mesoderm, <br />and the dorsal ectoderm has<br />thickened, forming the neural plate, <br />in response to signals from the<br />notochord. The neural folds are<br />the two ridges that form the lateral <br />edges of the neural plate. These <br />are visible in the light micrograph<br />of a whole embryo.<br />(a)<br />Figure 47.14a<br /><ul><li>Early in vertebrate organogenesis
    20. 20. The notochord forms from mesoderm and the neural plate forms from ectoderm</li></li></ul><li>Neural<br />fold <br />Neural plate<br />Neural crest<br />Outer layer <br />of ectoderm<br />Neural crest<br />Neural tube<br />(b)<br />Formation of the neural tube.<br />Infolding and pinching off of the <br />neural plate generates the neural tube. <br />Note the neural crest cells, which will <br />migrate and give rise to numerous<br />structures.<br />Figure 47.14b<br /><ul><li>The neural plate soon curves inward
    21. 21. Forming the neural tube</li></li></ul><li>Eye<br />Somites<br />Tail bud<br />SEM<br />Neural tube<br />1 mm<br />Notochord<br />Neural<br />crest<br />Coelom<br />Somite<br />Archenteron<br />(digestive cavity)<br />Somites. The drawing shows an embryo<br />after completion of the neural tube. By <br />this time, the lateral mesoderm has<br />begun to separate into the two tissue<br />layers that line the coelom; the somites, <br />formed from mesoderm, flank the<br />notochord. In the scanning electron <br />micrograph, a side view of a whole <br />embryo at the tail-bud stage, part of the <br />ectoderm has been removed, revealing<br />the somites, which will give rise to <br />segmental structures such as vertebrae <br />and skeletal muscle.<br />(c)<br />Figure 47.14c<br /><ul><li>Mesoderm lateral to the notochord
    22. 22. Forms blocks called somites
    23. 23. Lateral to the somites
    24. 24. The mesoderm splits to form the coelom</li></li></ul><li>neurula<br />
    25. 25.
    26. 26. Level of telencephalon<br />Level of heart<br />Level of hindgut<br />Level of midgut<br />Level of eyes<br /><br />
    27. 27. GENETICS<br />
    28. 28. Vocabulary<br /><ul><li>Genetics: The scientific study of heredity
    29. 29. Allele: Alternate forms of a gene/factor.
    30. 30. Genotype: combination of alleles an organism has.
    31. 31. Phenotype: How an organism appears.
    32. 32. Dominant: An allele which is expressed (masks the other).
    33. 33. Recessive: An allele which is present but remains unexpressed (masked)
    34. 34. Homozygous: Both alleles for a trait are the same.
    35. 35. Heterozygous: The organism's alleles for a trait are different.</li></li></ul><li>Composition of DNA<br />The structure of DNA was discovered by Watson and Crick in 1953.<br />It is a twisted double helix molecule, containing sugar, phosphates, and nitrogenous bases.<br />The sugar is deoxyribose and the phosphoric acid molecules are always the same and provides for the structure (side of the ladder).<br />The only difference between us is the order and arrangement of the four bases (rungs of the ladder).<br />
    36. 36. Bases of DNA<br />Adenine= A<br />Thymine= T<br />Guanine= G<br />Cytosine= C<br />A always pairs with T<br />C always pairs with G<br />
    37. 37. Bases of RNA<br />Adenine= A<br />Uracil= U<br />Guanine= G<br />Cytosine= C<br />G always pairs with C<br />T from the DNA = A in the RNA<br />A from the DNA = U in the RNA<br />
    38. 38. DNA Model<br />
    39. 39. Chromosomes<br />The DNA in every cell is located in rod like segments called chromosomes<br />Chromosomes occurs in pairs in every cell of our body except in the sperm and ovum.<br />Chromosomes numbers are the same for each specie.<br />
    40. 40. Chromosome Numbers<br />Species Diploid # Haploid #<br />Cattle 60 30<br />Swine 38 19<br />Sheep 54 27<br />Horse 64 32<br />Human 46 23<br />Chicken 78 39<br />Goat 60 30<br />Donkey 62 31<br />
    41. 41. Chromosomes<br />There are 2 sex chromosomes included in the diploid number of the chromosomes.<br />All of the other chromosomes are referred to as autosomes. <br />In mammals if the sex chromosomes are alike, XX it results in a female.<br />If the sex chromosomes are different, XY it results in a male.<br />
    42. 42. Sex Determination<br />Females contribute an X chromosome towards the sex of their offspring.<br />Males can contribute an X or a Y chromosome toward the sex of their offspring.<br />Absence of an Y chromosome results in a the embryo developing into a female.<br />Presence of an Y chromosome results in the embryo developing into a male.<br />
    43. 43. Sex Determination<br />Gametogenesis = Formation of gametes through meiosis.<br />Male = 4 viable spermatids<br />Female = 1 viable ovum, 3 polar bodies.<br />
    44. 44. Laws of Inheritance<br /><ul><li>Law of Segregation: When gametes (sperm egg etc…) are formed each gamete will receive one allele or the other.
    45. 45. Law of independent assortment: Two or more alleles will separate independently of each other when gametes are formed </li></li></ul><li>Mendelian Genetics<br />While assigned to teach, he was also assigned to tend the gardens and grow vegetables for the monks to eat.<br />Augustinian Monk at Brno Monastery in Austria (now Czech Republic)<br />Not a great teacher but well trained in math, statistics, probability, physics, and interested in plants and heredity.<br />Mountains with short, cool growing season meant pea (Pisum sativum) was an ideal crop plant.<br />Gregor Mendel<br />“Father of Genetics”<br />
    46. 46. Mendel worked with peas (Pisum sativum)<br /><ul><li>Good choice for environment of monastery
    47. 47. Network provided unusual varieties for testing
    48. 48. Obligate self-pollination reproductive system
    49. 49. Permits side-by-side genetic barriers
    50. 50. Cross-pollinations require intentional process
    51. 51. Crosses meticulously documented
    52. 52. Crosses numerically/statistically analyzed</li></li></ul><li>One Example of Mendel’s Work<br />Tall<br />Dwarf<br />x<br />Phenotype<br />P<br />TT<br />tt<br />Genotype<br />Homozygous<br />Dominant<br />Homozygous<br />Recessive<br />All Tall<br />Clearly Tall is Inherited…<br />What happened to Dwarf?<br />F1<br />Tt<br />Tall is dominant to Dwarf<br />Heterozygous<br />F1 x F1 = F2<br />possible gametes<br />Punnett Square:<br />t<br />T<br />3/4 Tall<br />1/4 Dwarf<br />F2<br />Tall<br />Tt<br />Tall<br />TT<br />T<br />possible gametes<br />Dwarf<br />tt<br />Tall<br />Tt<br />t<br />Dwarf is not missing…just masked as “recessive” in a diploid state… there IS a female contribution.<br />
    53. 53. F1 x F1 = F2<br />F2<br />possible gametes<br />Punnett Square:<br />t<br />T<br />Tall<br />tt<br />Tall<br />TT<br />T<br />possible gametes<br />Dwarf<br />tt<br />Tall<br />Tt<br />t<br />Mendel as a Scientist<br />Test Cross:<br />Unknown Tall<br />Dwarf<br />x<br />tt<br />possible gametes<br />If Unknown is TT:<br />t<br />t<br />Tall<br />Tt<br />Tall<br />Tt<br />T<br />possible gametes<br />Test Progeny All Tall<br />Tall<br />Tt<br />Tall<br />Tt<br />T<br />1/3 of F2 Tall are TT<br />2/3 of F2 Tall are Tt<br />possible gametes<br />If Unknown is Tt:<br />t<br />t<br />Tall<br />Tt<br />Tall<br />Tt<br />T<br />possible gametes<br />Test Progeny Half Tall Half Dwarf<br />Dwarf<br />tt<br />Dwarf<br />tt<br />t<br />
    54. 54. Another Example of Mendel’s Work<br />Green<br />Yellow<br />x<br />Phenotype<br />P<br />gg<br />GG<br />Genotype<br />Homozygous<br />Recessive<br />Homozygous<br />Dominant<br />All Yellow<br />Clearly Yellow is Inherited…<br />What happened to Green?<br />F1<br />Gg<br />Yellow is dominant to Green<br />Use G/g rather than Y/y for symbolic logic<br />Heterozygous<br />F1 x F1 = F2<br />possible gametes<br />NEVER use G/Y or g/y<br />Punnett Square:<br />g<br />G<br />3/4 Yellow<br />1/4 Green<br />F2<br />Yellow<br />Gg<br />Yellow<br />GG<br />G<br />possible gametes<br />Green<br />gg<br />Yellow<br />Gg<br />g<br />Green is not missing…just masked as “recessive” in diploid state<br />
    55. 55. F1 x F1 = F2<br />F2<br />possible gametes<br />Punnett Square:<br />g<br />G<br />Yellow<br />Gg<br />Yellow<br />GG<br />G<br />possible gametes<br />Green<br />gg<br />Yellow<br />Gg<br />g<br />Mendel as a Scientist<br />Test Cross:<br />Unknown Yellow<br />Green<br />x<br />gg<br />possible gametes<br />If Unknown is GG:<br />g<br />g<br />Yellow<br />Gg<br />Yellow<br />Gg<br />G<br />possible gametes<br />Test Progeny All Yellow<br />Yellow<br />Gg<br />Yellow<br />Gg<br />G<br />1/3 of F2 Yellow are GG<br />2/3 of F2 Yellow are Gg<br />possible gametes<br />If Unknown is Gg:<br />g<br />g<br />Yellow<br />Gg<br />Yellow<br />Gg<br />G<br />possible gametes<br />Test Progeny Half Yellow Half Green<br />Green<br />gg<br />Green<br />gg<br />g<br />
    56. 56. Mendel worked with peas (Pisum sativum)<br /><ul><li>Good choice for environment of monastery
    57. 57. Network provided unusual varieties for testing
    58. 58. Obligate self-pollination reproductive system
    59. 59. Permits side-by-side genetic barriers
    60. 60. Cross-pollinations require intentional process
    61. 61. Crosses meticulously documented
    62. 62. Crosses numerically/statistically analyzed
    63. 63. Scientists of 1860s could not understand math
    64. 64. Work lost in journals for 50 years!
    65. 65. Rediscovered in 1900s independently by 3 scientists
    66. 66. Recognized as landmark work!</li></li></ul><li>After 1900 several scientists tried to replicate Mendel’s crosses using other species including snapdragon.<br />Genetics After Mendel<br />Red<br />Yellow<br />P<br />x<br />PRPR<br />PYPY<br />When these alleles go walking, they both do some talking (codominance)!<br />OK, so we cannot use R/r nor Y/y so we pick a third letter…P for the petal color gene.<br />Notice: we do NOT mix R/Y or r/y!<br />All Orange<br />F1<br />PRPY<br />F1 x F1 = F2<br />possible gametes<br />Punnett Square:<br />PY<br />PR<br />F2<br />Orange<br />PRPY<br />Red<br />PRPR<br />PR<br />This F2 will NOT have a 3:1 ratio of phenotypes.<br />Instead it shows a 1:2:1 ratio!<br />The exception here proves the rule.<br />possible gametes<br />Yellow<br />PYPY<br />Orange<br />PRPY<br />PY<br />
    67. 67. In addition to this, there are multiple alleles possible:<br />PR = red PY = yellow p = no pigment<br />The combination of alleles in a diploid determine the flower color:<br />PRPR = red<br />PRPY = orange<br />PYPY = yellow<br />PRp = pink<br />PYp = cream<br />pp = white<br />Human hair color follows a similar pattern:<br />Alleles: HBn = brown HBd = blonde hR = red hbk = black<br />The combinations of these alleles determine the base hair color:<br />HBnHBn = dark brown<br />HBnHBd = sandy brown<br />HBnhR = auburn<br />HBnhbk = dark brown<br />HBdHBd = blonde<br />HBdhR = strawberry blonde<br />HBdhbk = blonde<br />hRhR = red<br />hRhbk = red<br />hbkhbk = black<br />Recessive can be common!<br />Dominant does NOT mean frequent!<br />
    68. 68. Another Example of Recessive Being Common: Pisum sativum<br />Garden Peas: green seed, wrinkled seed, dwarf stature, white flower<br />gg<br />ww<br />dd<br />aa<br />In other words: a quadruple double-recessive<br />is the most common garden pea on Earth!<br />Quantitative Inheritance: multiple genes control trait<br /> Highest Crop Yield: AABBCCDDEE<br />Intermediate Crop Yield: AabbCCDdEe<br /> Lowest Crop Yield: aabbccddee<br /> Darkest Skin Color: AABBCCDDEE<br />Intermediate Skin Color: AaBbCcDdEe<br /> Lightest Skin Color: aabbccddee<br />AaBbCcDdEe x AaBbCcDdEe can produce a huge range of colors!<br />
    69. 69. Phenotype = Genotype + Environment<br />Crop Yield = Genotype<br /> + Minerals<br /> + Water<br /> + Light<br /> - Pests<br /> etc.<br />Optimizing these factors determines agricultural productivity…last part of our course!<br />Human Skin Color = Genotype<br /> + Sun (UV) Exposure<br /> - Aging Factors<br />The sun exposure effect is most obvious in people of intermediate skin base color<br />but everyone can have “tan lines.”<br />
    70. 70. Who Gets To Mate With Whom? …Two Extremes<br />Inbreeding Depression: related parents give same recessives to children<br />Hemophilia: Queen Victoria’s Mutation and Diseased Grandchildren<br />  recessive sex-linked, X chromosome disorders, haemophilia is more likely to occur in males than females<br />Tay-Sachs: Jewish Populations<br />Recessive autosomal disease; relentless deterioration of mental and physical abilities<br />Hybrid Vigor:<br />Wild Corn A x Wild Corn B<br />High Yield Hybrid Corn!<br />
    71. 71. Tree method crossing of two traits(dihybrid)<br />
    72. 72. Continuous Variation<br />Many traits may have a wide range of continuous values. Eg. Human height can vary considerably. There are not just "tall" or "short" humans <br />
    73. 73. <ul><li>Gene interaction:
    74. 74. Many biological pathways are governed by multiple enzymes, involving multiple steps. If any one of these steps are altered. The end product of the pathway may be disrupted.
    75. 75. Environmental effects:
    76. 76. Sometimes genes will not be fully expressed owing to external factors. Example: Human height may not be fully expressed if individuals experience poor nutrition.</li></li></ul><li>The Average American Phenotype<br />
    77. 77. Ecosystems: Basic Concepts<br />
    78. 78. What is an ecosystem?<br />System= regularly interacting and interdependent components forming a unified whole<br />Ecosystem = an ecological system;= a community and its physical environment treated together as a functional system<br />
    79. 79. Ecosystem Services<br />The human economy depends upon the services performed for free by ecosystems. <br />The ecosystem services supplied annually are worth many trillions of dollars. <br />Economic development that destroys habitats and impairs services can create costs to humanity over the long term that may greatly exceed the short-term economic benefits of the development.<br />These costs are generally hidden from traditional economic accounting, but are nonetheless real and are usually borne by society at large.<br /><br />
    80. 80. Ecosystems:Fundamental Characteristics<br />Structure:<br /> Living (biotic)<br /> Nonliving (abiotic)<br />Process:<br /> Energy flow<br /> Cycling of matter (chemicals)<br />Change:<br /> Dynamic (not static)<br /> Succession, etc.<br />
    81. 81. Abiotic components:<br />ABIOTIC components:<br />Solar energy provides practically all the energy for ecosystems.<br />Inorganic substances, e.g., sulfur, boron, tend to cycle through ecosystems.<br />Organic compounds, such as proteins, carbohydrates, lipids, and other complex molecules, form a link between biotic and abiotic components of the system. <br />
    82. 82. BIOTIC components<br />The biotic components of an ecosystem can be classified according to their mode of energy acquisition.<br />In this type of classification, there are:<br />Autotrophs and Heterotrophs<br />Organisms that produce their own food from an energy source, such as the sun, and inorganic compounds.<br />Organisms that consume other organisms as a food source.<br />
    83. 83. Trophic level: All the organisms that are the same number of food-chain steps from the primary source of energy<br />Modified from: General Ecology, by David T. Krome<br />
    84. 84. Trophic Levels<br />A trophic level is the position occupied by an organism in a food chain.<br />Trophic levels can be analyzed on an energy pyramid.<br />Producers are found at the base of the pyramid and compromise the first trophic level. <br />Primary consumers make up the second trophic level.<br />Secondary consumers make up the third trophic level.<br />Finally tertiary consumers make up the top trophic level.<br />
    85. 85. Trophic Levels Found on an Energy Pyramid<br />The greatest amount of energy is found at the base of the pyramid.<br />The least amount of energy is found at top of the pyramid.<br />Source: <br />
    86. 86. Food Chains<br />The producers, consumers, and decomposers of each ecosystem make up a food chain.<br />There are many food chains in an ecosystem.<br />Food chains show where energy is transferred and not who eats who.<br />
    87. 87. Example of a Food Chain<br />
    88. 88. Food Webs<br />All the food chains in an area make up the food web of the area.<br />
    89. 89. Changes in Ecosystems:Ecological Succession<br />
    90. 90. Definition:<br />Natural, gradual changes in the types of species that live in an area; can be primary or secondary <br />The gradual replacement of one plant community by another through natural processes over time<br />
    91. 91. Primary Succession<br />Begins in a place without any soil <br />Sides of volcanoes<br />Landslides<br />Flooding<br />Starts with the arrival of living things such as lichens that do not need soil to survive<br />Called PIONEER SPECIES<br />
    92. 92.<br /><br />
    93. 93. Primary Succession<br />Soil starts to form as lichens and the forces of weather and erosion help break down rocks into smaller pieces<br />When lichens die, they decompose, adding small amounts of organic matter to the rock to make soil <br />
    94. 94.<br />
    95. 95. Primary Succession<br />Simple plants like mosses and ferns can grow in the new soil <br /><br /><br />
    96. 96. Primary Succession<br />The simple plants die, adding more organic material<br />The soil layer thickens, and grasses, wildflowers, and other plants begin to take over <br /><br />
    97. 97. Primary Succession<br />These plants die, and they add more nutrients to the soil<br />Shrubs and tress can survive now<br /><br />
    98. 98. Primary Succession<br />Insects, small birds, and mammals have begun to move in<br />What was once bare rock now supports a variety of life <br /><br />
    99. 99. Secondary Succession<br />Begins in a place that already has soil and was once the home of living organisms <br />Occurs faster and has different pioneer species than primary succession <br />Example: after forest fires<br />
    100. 100.<br />
    101. 101. Climax Community<br />A stable group of plants and animals that is the end result of the successionprocess<br />Does not always mean big trees<br />Grasses in prairies<br />Cacti in deserts<br />
    102. 102. Symmetry and Body Plan<br />
    103. 103. Symmetry<br />Arrangement of parts with regard to the axes and planes.<br />Way a body parts is arranged around a center point<br />4 fundamental types of animal symmetry:<br />Spherical or universal<br />Radial<br />Biradial or radiobilateral<br />Bilateral<br />
    104. 104. Asymmetry<br />Anaxial symmetry<br />Body cannot be divided by planes into similar halves<br />Body is irregularly shaped<br />No definite anatomical relationship between different parts<br />
    105. 105. Asymmetry<br />
    106. 106. Universal or Spherical<br />Homoaxial symmetry<br />Symmetry exists in an organism that can be dissected into equal or identical halves by any of the infinite axes and planes that transect it.<br />Assumes shape of ball<br />Body parts arranged concentrically around or radiating from a central point<br />
    107. 107. Universal<br />
    108. 108. Radial Symmetry<br />Monoaxialheteropolar symmetry<br />Organism assumes shape of a cylinder with parts arranged around and along a single central axis in which 2 ends are different: mouth and anus<br />Central axis is referred as longitudinal, oral-aboral or antero-posterior axis.<br />Plane passing through axis dividing organism into similar halves.<br />
    109. 109. Radial Symmetry<br />
    110. 110. Biradial symmetry<br />Dissymmetry<br />
    111. 111. Bilateral Symmetry<br />only the transverse axis has similar ends.<br />Antero-posterior axis and dorso-ventral axis<br />Divides animal into right and left with mirror images<br />
    112. 112. Bilateral Symmetry<br />
    113. 113. Asymmetrical – without a balanced arrangement of similar parts on either side of a point or axis<br />Radial - any plane passing through the oral-aboral axis divides an organism to mirror images<br />Bilateral – only the midsagittal plane divides an organism to mirror images. Have definite anterior (head) and posterior (tail) ends<br />
    114. 114. Other Features of animal Forms<br />Antimeres – identical and asymmetrically corresponding parts of an animal.<br />Arms of a starfish<br />
    115. 115. Other Features of Animal Forms<br />Metamerism – division of body into segments or metameres.<br />Segmentation may be superficial or external (false) OR may include internal organs (true)<br />Segments may be similar (homonomous) OR different from each other (heternomous)<br />
    116. 116. Other Features of Animal Forms<br />Cephalization – differentiation of anterior end of animal and is characterized by concentration of nervous elements such as formation of brain and sense organs.<br />Well-developed head region<br />
    117. 117. Other Features of Animal Forms<br />Tagmatization or tagmosis – union of segments into larger functional groups.<br />Each special group is a tagma (plural, tagmata)<br />
    118. 118. Animal Diversity<br />
    119. 119. Why Things are Grouped<br /> Put things in order<br /> Easier to find<br /> Show that things share certain traits<br />
    120. 120. Methods of Classification<br /> Early Classification<br /> Aristotle <br /> Plants and Animals<br /> Plants (Green & Didn’t Move)<br /> Animals (Weren’t Green & Move)<br />
    121. 121. Aristotle’s Classification<br /> Animals<br /> Land, Water, Air<br />Plants<br /> Size of plant<br /> Pattern of Growth<br />
    122. 122. Aristotle’s Classification<br />
    123. 123. Methods of Classification<br /> New Classification<br />Carolus Linnaeus (1735)<br /> 2 main groups: Kingdom<br /> Use specific traits into same group and called it species<br /> Placed similar species to larger group called genus<br />
    124. 124. Linnaeus<br /> Important Changes in Aristotle’s System:<br />Plants and Animals into more groups<br />Based his system on specific traits<br />Gave organisms names that described their traits<br /><ul><li>Living things had 2-part names:</li></ul>Genusspecies<br />
    125. 125. Classification System<br />
    126. 126. Classifying Organisms<br /> Kingdom<br /> Phylum<br /> Class<br /> Order<br /> Family<br /> Genus<br /> Species<br />
    127. 127. Classification<br />
    128. 128. How Scientists Classify Today<br /> Look at Traits<br /> Compare traits of one organism with those of another.<br /> Compare organisms living today with those that lived long ago.<br />
    129. 129. Classifying Based on How Organisms are Related<br />Classifying the House Cat<br />
    130. 130. Other Evidence Used in Classifying<br /> Based on living thing’s ancestors<br /> Horses and donkeys have many same ancestors<br /> Similar body structures<br /> Human and cat have similar front limbs and similar bones arranged in similar patterns<br /> Body chemistry<br /> Horseshoe crab’s blood is similar to spider<br />
    131. 131. Scientific Name Comes from Classification<br />
    132. 132. Why Scientific Names are Used<br /> No mistakes can be made about which living thing is described.<br /> Scientific names seldom change.<br /> Scientific names are written in the same language around the world.<br />
    133. 133. Kingdom Classification<br />Animal<br />Plant<br />Fungi<br />Protist<br />Monera<br />
    134. 134.
    135. 135. Modern Classification<br /> Seven groups – Kingdom, phylum, class, order, family, genus, species<br /> Evidence – Same ancestors, similar body structure, body chemistry<br /> Organisms given 2-part scientific names<br /> Kingdoms – Moneran, Protist, Fungus, Plant, Animal<br />
    136. 136. Overview of Animal Diversity and Phylogeny<br /><ul><li>Diversified during Precambrian and Cambrian periods
    137. 137. Monophyletic
    138. 138. Parazoans-first branch, lack true tissues
    139. 139. Radiata and bilateria two major branches of Eumetazoa
    140. 140. Evolution of body cavities
    141. 141. Protostomes and deuterostomes</li></li></ul><li>
    142. 142. Parazoa<br /><ul><li>Sponges
    143. 143. “beside the animals”
    144. 144. Simple aquatic and marine forms</li></li></ul><li>Eumetazoa<br />Two major branches:<br /><ul><li> 1. Radiata-radial symmetry, top and </li></ul> bottom, no front, back, or sides, <br /> diploblastic larva<br /><ul><li> 2. Bilateria-bilateral symmetry, triploblastic,</li></ul> cephalization <br />
    145. 145.
    146. 146. Importance of Coelom<br /><ul><li>Acoelomates-no body cavity, Platyhelminthes
    147. 147. Pseudocoelomates-fluid filled body cavity, </li></ul> partially lined with mesoderm, Nematoda<br /><ul><li>Coelomates-fluid filled, completely lined with mesoderm, Annelida
    148. 148. Coelom-body cavity that protects internal organs</li></li></ul><li>
    149. 149. Protostomes and Deuterostomes<br />Protostomes:<br /><ul><li>Mollusks, Annelids, Arthropods
    150. 150. Spiral cleavage
    151. 151. Determinate cleavage
    152. 152. Blastopore forms the mouth
    153. 153. schizocoelous</li></ul>Deuterostomes:<br /><ul><li>Echinoderms and Chordates
    154. 154. Radial cleavage
    155. 155. Indeterminate cleavage
    156. 156. Blastopore forms the anus
    157. 157. Enterocoelous</li></li></ul><li>
    158. 158. The Origins of Animal Diversity<br /><ul><li>Colonial protist origin during Cambrian Explosion
    159. 159. Evidence from fossil beds: Burgess Shale, Yunnan region, Greenland
    160. 160. Why such rapid diversification?</li></ul> 1. Adaptive radiation<br /> 2. Predator-prey relationships<br /> 3. Higher concentration of oxygen<br />
    161. 161. Porifera - Sponges<br />No symmetry<br />No organs<br />The least complex animals<br />Aquatic in fresh and marine environments<br />
    162. 162. water out<br />glasslike structural elements<br />amoeboid cell<br />pore<br />semifluid matrix<br />central cavity<br />flattened surface cells<br />water in<br />flagellum<br />microvilli<br />nucleus<br />Body Plan of a Sponge<br />
    163. 163. Venus’s flower basket (Euplectella)<br />
    164. 164. Cnidaria<br />Radial symmetry<br />Body has only 2 cell layers<br />Mouth surrounded by tentacles with stinging cells<br />Aquatic, FW and marine<br />Include jellyfish, corals, sea anemones, hydra<br />Some are motile, and all have a very simple nervous system<br />Respiration: direct gas exchange with aquatic surroundings<br />
    165. 165. There are two Cnidarian body plans<br />Polyp<br />outer epithelium (epidermis)<br />mesoglea<br />(matrix)<br />inner epithelium (gastrodermis)<br />Medusa<br />
    166. 166. reproductive polyp<br />female medusa<br />male medusa<br />sperm<br />ovum<br />Life cycle of Obelia<br />feeding polyp<br />zygote<br />planula<br />polyp forming<br />branching<br />one branch from a mature colony<br />
    167. 167. Flatworms - Platyhelminthes<br />Body has 3 cell layers: ectoderm, mesoderm and endoderm<br />Bilateral symmetry<br />Parasitic and free -living aquatic (fw and marine) and terrestrial: tapeworms, flukes, and Planaria<br />Digestive system with one opening<br />Primitive nervous system<br />Hermaphroditic<br />Respiration through skin<br />
    168. 168. pharynx (protruded)<br />protonephridia<br />flame cell<br />nucleus<br />cilia<br />fluid <br />filters through membrane folds<br />Planaria, a free-living flatworm<br />opening of tubule at body surface<br />flame cell<br />
    169. 169. brain<br />nerve cord<br />genital pore<br />testis<br />penis<br />oviduct<br />ovary<br />
    170. 170. b A definitive host eats infected, undercooked beef<br />a Larvae become encysted in intermediate host tissues <br />c Scolex of larva attaches to intestine’s wall <br />d Many proglottids form by budding<br />f Cattle may ingest embryonated eggs or ripe proglottids to become intermediate hosts<br />e Ripe proglottids containing fertilized eggs leave host in feces <br />Tapeworm life cycle<br />
    171. 171. Roundworms - Nematoda<br />Digestive system with mouth and anus (“complete”)<br />Separate sexes<br />Aquatic and terrestrial, free living and parasitic<br />Body cavity gives “tube within a tube” construction<br />Respiration through skin, no circulatory system<br />
    172. 172. Body Plan of a Roundworm<br />gonad<br />pharynx<br />intestine<br />eggs in uterus<br />anus<br />false coelom<br />muscularized body wall<br />Caenorhabditiselegans<br />
    173. 173.  Life cycle of Schistosoma japonicum<br />
    174. 174. Mollusks - Mollusca<br />Often but not always have external shell<br />Includes clams, oysters, snails, slugs, squid, octopus, scallops, chambered nautilus<br />Body is soft with bilateral symmetry<br />Nervous system, circulatory system, respiratory system<br />Some have excellent sense organs and large brains, and can learn easily. <br />
    175. 175. Body Plan of a Snail<br />anus<br />gill<br />mantle cavity<br />excretory organ<br />heart<br />digestive gland<br />shell<br />stomach<br />mantle<br />radula<br />foot<br />
    176. 176. Body Plan of a Cuttlefish<br />esophagus<br />stomach<br />kidney<br />digestive gland<br />brain<br />arm<br />jaw<br />mantle<br />reproductive organ<br />internal shell<br />siphon<br />ink sac<br />heart<br />accessory heart<br />tentacle<br />radula<br />anus<br />gill<br />
    177. 177. Segmented Worms - Annelida<br />Body composed of many identical segments. Allows more specialization<br />Aquatic or terrestrial<br />Includes clam worm, feather worms, leeches, and earthworm.<br />These animals have “all” systems, and are quite complex. They are most likely the ancestors of the Arthropods, the most successful Phylum of animals on Earth.<br />
    178. 178. “jaws”<br />toothlike structures<br />pharynx (everted)<br />antenna<br />palp <br />(food handling)<br />tentacle<br />eyes<br />chemical-sensing pit<br />parapod<br />
    179. 179.
    180. 180. <ul><li>Taxonomy is the science of grouping</li></ul> and naming organisms.<br /><ul><li>Classification the grouping of </li></ul> information or objects based on<br /> similarities.<br /><ul><li> The scientific name comes from one of two</li></ul> “dead” languages – Latin or ancient Greek. <br />
    181. 181.     <br /><ul><li>a two name system for writing scientific names.
    182. 182. The genus name is written first (always Capitalized).    
    183. 183. The species name is written second (never capitalized).    
    184. 184. Both words are </li></ul> italicized if typed or underlined if hand written. <br />Example: Felis concolor or F. concolor<br />Which is the genus? The species?<br />    <br />Binomial Nomenclature<br />
    185. 185. "Formal" scientific names should have a third part, the authority.     The authority is not italicized or underlined. <br />The authority is written as an abbreviation of the last name of the person responsible for naming the organism. Since Carolus Linnaeus was the first person to name many plants, the L. for Linnaeus is very common in plant scientific names. <br />An example is Quercus alba L.<br />