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  2. Biological life cycle - Wikipedia

    en.wikipedia.org/wiki/Biological_life_cycle

    Reproduction completes and perpetuates the cycle. In biology, a biological life cycle (or just life cycle when the biological context is clear) is a series of stages of the life of an organism, that begins as a zygote, often in an egg, and concludes as an adult that reproduces, producing an offspring in the form of a new zygote which then ...

  3. Timeline of the evolutionary history of life - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_the...

    [2] [3] Estimates on the number of Earth's current species range from 10 million to 14 million, [4] with about 1.2 million or 14% documented, the rest not yet described. [5] However, a 2016 report estimates an additional 1 trillion microbial species, with only 0.001% described. [6]

  4. Pteridophyte - Wikipedia

    en.wikipedia.org/wiki/Pteridophyte

    Pteridophyte life cycle. Just as with bryophytes and spermatophytes (seed plants), the life cycle of pteridophytes involves alternation of generations. This means that a diploid generation (the sporophyte, which produces spores) is followed by a haploid generation (the gametophyte or prothallus, which produces gametes). Pteridophytes differ ...

  5. Alternation of generations - Wikipedia

    en.wikipedia.org/wiki/Alternation_of_generations

    Alternation of generations (also known as metagenesis or heterogenesis) [1] is the predominant type of life cycle in plants and algae. In plants both phases are multicellular: the haploid sexual phase – the gametophyte – alternates with a diploid asexual phase – the sporophyte. A mature sporophyte produces haploid spores by meiosis, a ...

  6. Nutrient cycle - Wikipedia

    en.wikipedia.org/wiki/Nutrient_cycle

    A nutrient cycle (or ecological recycling) is the movement and exchange of inorganic and organic matter back into the production of matter. Energy flow is a unidirectional and noncyclic pathway, whereas the movement of mineral nutrients is cyclic. Mineral cycles include the carbon cycle, sulfur cycle, nitrogen cycle, water cycle, phosphorus ...

  7. Gametogenesis - Wikipedia

    en.wikipedia.org/wiki/Gametogenesis

    Gonochorism. Hermaphrodite. v. t. e. Gametogenesis is a biological process by which diploid or haploid precursor cells undergo cell division and differentiation to form mature haploid gametes. Depending on the biological life cycle of the organism, gametogenesis occurs by meiotic division of diploid gametocytes into various gametes, or by mitosis.

  8. Annual plant - Wikipedia

    en.wikipedia.org/wiki/Annual_plant

    An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. Globally, 6% of all plant species and 15% of herbaceous plants (excluding trees and shrubs) are annuals. [1] The annual life cycle has independently emerged in over 120 different plant families ...

  9. Continued fraction - Wikipedia

    en.wikipedia.org/wiki/Continued_fraction

    A finite regular continued fraction, where is a non-negative integer, is an integer, and is a positive integer, for . A continued fraction is a mathematical expression that can be writen as a fraction with a denominator that is a sum that contains another simple or continued fraction. Depending on whether this iteration terminates with a simple ...