plant reproduction

• What are the organs of reproduction for angiosperms?


  Flowers
• How do gymnosperms differ from angiosperms in terms of reproductive structures?


  Gymnosperms form other structures to contain their reproductive organs
• What determines the structure of flowers?

  The method of pollination
• What are the characteristics of insect-pollinated flowers?


  • Have a receptacle at the top of the flower stalk
  • Sepals protect the flower bud
  • Petals attract insects with color and patterns
  • Male reproductive organ consists of filament and anther
  • Female reproductive organ includes ovary, style, and stigma
  • May have nectaries to attract pollinators
• What is the function of the receptacle in a flower?


  It is the top of the flower stalk from which different parts develop
• What are sepals?


  Modified leaves that protect the flower while it’s still forming
• What is the role of petals in insect-pollinated flowers?


  They attract insects with their large, colored, and patterned appearance
• What is the male reproductive organ of a flower called?

  Stamen
• What are the components of the stamen?

  Filament and anther
• What occurs in the anther of a flower?


  Meiosis and mitosis to produce male gametes
• What does the carpel consist of?

  Ovary, style, and stigma
• What happens to the ovules after fertilization?


  They become seeds
• What is the function of nectaries in flowers?


  They secrete nectar to attract pollinators
• What are the characteristics of wind-pollinated flowers?


  • Petals are absent
  • No scent is produced
  • Nectaries are absent
  • Anthers and stigma hang outside the flower
  • Pollen is small, light, and may have air sacs
  • Very large quantities of pollen are produced
• What is the most common type of wind-pollinated flower?

  Grasses
• What do pollen grains contain?


  Male gametes of flowering plants
• Where are pollen grains formed?


  In the anthers
• What is the tapetum?


  A specialized layer of nutritive cells in the anther
• What is the role of the tapetum in pollen grain development?


  It provides nutrition for the development of pollen grains
• What happens to microspores after they are formed?


  The nuclei undergo mitosis to produce three genetically identical nuclei
• What are ovules also known as?


  Megaspores
• Where are female gametes formed in a flower?


  Within the embryo sac in the ovary
• What happens to the haploid cells produced from megaspore mother cells?


  Three degenerate, and one continues to develop
• How many mitotic divisions does the haploid nucleus undergo in the embryo sac?


  Three mitotic divisions
• What structures are formed around the nuclei in the embryo sac?


  Two synergids, one female gamete, and three antipodal cells
• What remains as free polar nuclei in the embryo sac?


  Two nuclei
• What is the process of megaspore formation in a flower?

  1. Megaspore mother cells undergo meiosis I and II.
  2. Four haploid cells are produced; three degenerate.
  3. One cell continues to develop.
  4. The haploid nucleus undergoes three mitotic divisions.
  5. Forms eight nuclei: two synergids, one female gamete, three antipodal cells, and two free polar nuclei.
• What is important to learn about the embryo sac?


  • Position of cells and nuclei
  • Names of the cells: synergids, female gamete, antipodal cells, and polar nuclei