Zoology review 2


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Zoology review 2

  1. 1. Zoology Review Growth & Reproduction
  2. 2. Animal Growth <ul><li>Young animals have a period of rapid growth </li></ul><ul><li>Growth occurs when cells reproduce more quickly than they die </li></ul><ul><li>Cell division that results in body growth is called mitosis </li></ul>
  3. 3. Five stages of mitosis <ul><li>Interphase – </li></ul><ul><ul><li>resting </li></ul></ul><ul><li>Prophase – </li></ul><ul><ul><li>chromosome formation </li></ul></ul><ul><li>Metaphase – </li></ul><ul><ul><li>chromosome alignment </li></ul></ul><ul><li>Anaphase – </li></ul><ul><ul><li>chromosome separation </li></ul></ul><ul><li>Telophase – </li></ul><ul><ul><li>Cell division </li></ul></ul>
  4. 4. Growth <ul><li>Mitosis is most active in young animals </li></ul><ul><li>Growth – cell masses expand the tissues </li></ul><ul><ul><li>Tissues make up organs </li></ul></ul><ul><ul><li>Organs make up systems </li></ul></ul><ul><ul><li>Systems make up organisms </li></ul></ul>
  5. 5. Animal Reproduction <ul><li>New organisms are created by the joining of reproductive cells called gametes </li></ul><ul><li>Gametes are formed by meiosis </li></ul><ul><li>Gametes are haploid cells </li></ul><ul><ul><li>Only contain ½ of genetic material required for life </li></ul></ul><ul><li>Parent cells are diploid </li></ul>
  6. 6. Fertilization <ul><li>Male and female gametes form a single cell – called a zygote </li></ul><ul><li>Zygotes are diploid </li></ul><ul><li>Many variations in development </li></ul><ul><li>Study of development is embryology </li></ul><ul><li>Fertilization may occur inside or outside of the body </li></ul>
  7. 7. Mammals <ul><li>Eggs are fertilized inside of the body </li></ul><ul><li>Zygotes develop to various stages of maturity inside the mother </li></ul><ul><li>Most young are born very dependent on maternal care </li></ul><ul><li>Varying degrees of development at birth </li></ul>
  8. 8. Amphibians & most fish <ul><li>Fertilization occurs outside of the body </li></ul><ul><li>No maternal care </li></ul><ul><li>Some fish give birth to live young </li></ul>
  9. 9. Birds & Most Reptiles <ul><li>Fertilization occurs inside the body </li></ul><ul><li>Fertilized eggs are covered with a protective shell as they pass thru the ovaduct </li></ul><ul><li>Eggs are laid to complete development </li></ul><ul><li>No or little maternal care </li></ul><ul><li>Some snakes give birth to live young </li></ul>