SPGBIO2_L1

• Asexual reproduction


  Mode of reproduction that does not involve the use of gametes or sex cells
• Types of Asexual Reproduction

  • Fission
  • Fragmentation
  • Budding
  • Sporulation
  • Parthenogenesis
• Fission


  Type of asexual reproduction involving the division of body into two or more equal parts
• Fragmentation


  Type of asexual reproduction where the body breaks into two or more parts, with each fragment capable of becoming a complete individual; in animals, fragmentation is usually followed by regeneration where the missing parts are produced
• Budding


  Type of asexual reproduction where a new individual arises as an outgrowth (bud) from its parent, develops organs like those of the parent, and then detaches itself
• Sporulation


  Type of asexual reproduction where new individual forms from an aggregation of cells surrounded by a resistant capsule or spore, which later on germinates
• Parthenogenesis


  A form of asexual reproduction by self-impregnation resulting in the production of a zygote from an unfertilized egg
• Sexual reproduction


  Mode of reproduction that involves the use of gametes or sex cells
• Types of union of gametes


  • Conjugation
  • Isogamy
  • Heterogamy
• Conjugation


  A form of sexual reproduction in bacteria where two individual cells are united by a tube formed by outgrowths from one or both cells, and genetic material from one cell (designated the male) then passes through the tube to unite with genetic material in the other cell (designated female)
• Isogamy


  Fusion of similar gametes which are usually motile
• Heterogamy


  Fusion of dissimilar gametes, where a large immotile gamete (the egg) is fertilized by a small motile gamete (the sperm)
• Special terms used for Sexual reproduction


  • Bisexual reproduction
  • Hermaphrodite
• Bisexual reproduction


  Type of sexual reproduction involving the union of gametes from two genetically different parents
• Hermaphrodite


  An individual with both male and female reproductive tissues. In animals "self-fertilization" is not common. In worms, a hermaphrodite needs a male to donate sperms in order to fertilize the oocytes in its body.
• Stages of Animal Development

  • Gametogenesis
  • Fertilization
  • Cleavage
  • Gastrulation
  • Organogenesis
  • Differentiation and Growth
• Gametogenesis


  The process by which diploid precursor cells undergo meiotic division to become haploid gametes (sex cells)
• Gametogenesis processes

  • Spermatogenesis
  • Oogenesis
• Spermatogenesis


  The production of spermatozoa (sperm) in the seminiferous tubules of the testes
• Oogenesis


  The production of female gametes (ova) within the ovaries (and, to a lesser extent, the oviduct)
• Oogenesis


  1. Formation of primordial cells by mitosis

  2. Cell growth of oogonia until they are large enough to undergo meiosis

  3. Meiosis of primary oocytes arrested in prophase I

  4. Completion of meiosis I to form secondary oocyte and polar body

  5. Arrest of secondary oocyte in metaphase II

  6. Ovulation and fertilization to complete meiosis II
• Key differences between spermatogenesis and oogenesis include the number of cells produced, the size of the cells, and the timing of the process
• Fertilization


  A stage of development that results in a unicellular diploid zygote
• Types of Fertilization

  • External Fertilization
  • Internal Fertilization
• External Fertilization


  Fusion of gametes (egg and sperm) outside of the body of a parent, common in aquatic animals
• Internal Fertilization


  Fusion of gametes (egg and sperm) inside of the body of a parent, requires a method by which the gamete of one parent can be introduced inside the body of another
• Cleavage


  A stage of development involving a series of mitotic divisions to produce a multicellular blastula from a unicellular zygote
• Totipotent cells


  Cells capable of differentiating to become any kind of cell
• Gastrulation


  A stage of development involving morphogenetic movements of the cells to produce a gastrula with distinct germ cell layers
• Organogenesis


  A stage of development where the different germ layers differentiate into specific organ systems
• The different germ layers (ectoderm, mesoderm, endoderm) give rise to specific tissues and organs in vertebrate animals
• Growth


  A stage of development characterized by an increase in size of an individual
• Development


  The formation of sex cells, zygote formation, and subsequent stages in one's life span, terminated by death
• The reproductive system is the system involved in the production of offspring in humans
• Female Reproductive Organs


  • Ovaries
  • Uterine tubes (fallopian tubes)
  • Uterus
  • Vagina
  • External genitalia
  • Mammary glands
• Ovaries


  Organs that produce female sex cells
• Fallopian tubes


  Tubes that extend from the ovaries to the uterus, where fertilization usually occurs
• Uterus


  Pear-shaped organ where the fetus develops during pregnancy
• Vagina


  Female organ for copulation and passage of menstrual flow and childbirth
• External genitalia


  Structures including the vestibule, labia minora, clitoris, and prepuce