microspore

Examples of microspore in the following topics:

• Sexual Reproduction in Angiosperms

  • The microsporangia, usually bi-lobed, are pollen sacs in which the microspores develop into pollen grains.
  • Within the microsporangium, the microspore mother cell divides by meiosis to give rise to four microspores, each of which will ultimately form a pollen grain .
  • An inner layer of cells, known as the tapetum, provides nutrition to the developing microspores, contributing key components to the pollen wall.
  • Each microsporangium contains hundreds of microspore mother cells that will each give rise to four pollen grains.
  • Pollen develops from the microspore mother cells.

• Life Cycle of a Conifer

  • Like all gymnosperms, pines are heterosporous, generating two different types of spores: male microspores and female megaspores.
  • The gametophytes (1n), microspores and megaspores, are reduced in size.

• Sexual Reproduction in Gymnosperms

  • The bracts, known as microsporophylls, are the sites where microspores will develop .
  • The microspores develop inside the microsporangium.
  • Within the microsporangium, cells known as microsporocytes divide by meiosis to produce four haploid microspores.
  • Further mitosis of the microspore produces two nuclei: the generative nucleus and the tube nucleus.

• Sporophytes and Gametophytes in Seedless Plants

  • The male spores are called microspores, because of their smaller size, and develop into the male gametophyte; the comparatively larger megaspores develop into the female gametophyte.
  • Heterosporous plants produce two morphologically different types of spores: microspores, which develop into the male gametophyte, and megaspores, which develop into the female gametophyte.

• Angiosperm Flowers

  • The filament supports the anther, where the microspores are produced by meiosis and develop into pollen grains .

• The Life Cycle of an Angiosperm

  • Therefore, they generate microspores, which will produce pollen grains as the male gametophytes, and megaspores, which will form an ovule that contains female gametophytes.
  • Inside the anthers' microsporangia, male gametophytes divide by meiosis to generate haploid microspores, which, in turn, undergo mitosis and give rise to pollen grains.

• Characteristics of Gymnosperms

  • One type of cone is the small pollen cone, which produces microspores that subsequently develop into pollen grains .

• Double Fertilization in Plants

  • The microspores, or the pollen, contain two cells: the pollen tube cell and the generative cell.