spore

Examples of spore in the following topics:

• Fungi Reproduction

  • Fungal spores are smaller and lighter than plant seeds.
  • The giant puffball mushroom bursts open and releases trillions of spores.
  • There are many types of asexual spores.
  • Other asexual spores originate in the fragmentation of a hypha to form single cells that are released as spores; some of these have a thick wall surrounding the fragment.
  • At this stage, spores are disseminated into the environment.

• Sporophytes and Gametophytes in Seedless Plants

  • Sporophytes (2n) undergo meiosis to produce spores that develop into gametophytes (1n) which undergo mitosis.
  • The term "sporangia" literally means "spore in a vessel": it is a reproductive sac that contains spores.
  • The spores are later released by the sporangia and disperse in the environment.
  • Seedless, non-vascular plants produce only one kind of spore and are called homosporous.
  • In contrast, heterosporous plants produce two morphologically different types of spores .

• Liverworts and Hornworts

  • The spore-producing cells undergo meiosis to form spores, which disperse (with the help of elaters), giving rise to new gametophytes.
  • The haploid spores germinate and produce the next generation of gametophytes .
  • Spores are released from sporophytes and form the gametophyte.
  • This sporophyte disperses spores with the help of elaters; the process begins again.
  • Liverworts also disperse their spores with the help of elaters, while hornworts utilize pseudoelaters to aid in spore dispersal.

• Life Cycles of Sexually Reproducing Organisms

  • The zygote immediately undergoes meiosis to form four haploid cells called spores.
  • The spores can remain dormant for various time periods.
  • The spores will subsequently develop into the gametophytes .
  • The zygote undergoes meiosis to produce haploid spores.
  • Each spore gives rise to a multicellular haploid organism by mitosis.

• Protist Life Cycles and Habitats

  • Meiosis produces haploid spores within the sporangia.
  • Spores disseminate through the air or water to potentially land in more favorable environments.
  • Cells atop the stalk form an asexual fruiting body that contains haploid spores.
  • As with plasmodial slime molds, the spores are disseminated and can germinate if they land in a moist environment.
  • The sporangium forms haploid spores through meiosis, after which the spores disseminate, germinate, and begin the life cycle anew.

• Zygomycota: The Conjugated Fungi

  • The black tips of bread mold, Rhizopus stolonifer, are the swollen sporangia packed with black spores .
  • When spores land on a suitable substrate, they germinate and produce a new mycelium.
  • When the zygospore germinates, it undergoes meiosis and produces haploid spores, which will, in turn, grow into a new organism.
  • The (b) tips of bread mold are the spore-containing sporangia.

• Seedless Vascular Plants

  • Seedless vascular plants, which reproduce and spread through spores, are plants that contain vascular tissue, but do not flower or seed.
  • In seedless vascular plants, such as ferns and horsetails, the plants reproduce using haploid, unicellular spores instead of seeds.
  • The spores are very lightweight (unlike many seeds), which allows for their easy dispersion in the wind and for the plants to spread to new habitats.

• Mosses

  • The most familiar structure is the haploid gametophyte, which germinates from a haploid spore and forms first a protonema: usually, a tangle of single-celled filaments that hug the ground.
  • A structure called a peristome increases the spread of spores after the tip of the capsule falls off at dispersal.
  • The concentric tissue around the mouth of the capsule is made of triangular, close-fitting units, a little like "teeth"; these open and close depending on moisture levels, periodically releasing spores.
  • The alternation of generations cycle begins when the gametophyte germinates from a haploid spore and forms a protonema.
  • Spores released from the sporophyte germinate and produce gametophytes; the process begins again.

• Characteristics of Gymnosperms

  • Gymnosperms are sporophytes (a plant with two copies of its genetic material, capable of producing spores).
  • Their sporangia (receptacle in which asexual spores are formed) are found on sporophylls, plated scale-like structures that together make up cones.
  • The female gametophyte develops from the haploid (meaning one set of genetic material) spores that are contained within the sporangia.
  • Like all seed plants, gymnosperms are heterosporous: both sexes of gametophytes develop from different types of spores produced by separate cones.

• Amoebozoa and Opisthokonta

  • For instance, during times of stress, some slime molds develop into spore-generating fruiting bodies, similar to fungi.
  • Haploid spores are produced by meiosis within the sporangia.
  • These spores can be disseminated through the air or water to potentially land in more favorable environments.
  • Cells atop the stalk form an asexual fruiting body that contains haploid spores.
  • As with plasmodial slime molds, the spores are disseminated and can germinate if they land in a moist environment.