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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. Cestoda - Wikipedia

    en.wikipedia.org/wiki/Cestoda

    Cestoda. Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, known as tapeworms. Their bodies consist of many similar units known as proglottids—essentially packages of eggs which are regularly shed ...

  4. Trematode life cycle stages - Wikipedia

    en.wikipedia.org/wiki/Trematode_life_cycle_stages

    The life cycle of a typical trematode begins with an egg. Some trematode eggs hatch directly in the environment (water), while others are eaten and hatched within a host, typically a mollusc. The hatchling is called a miracidium, a free-swimming, ciliated larva. Miracidia will then grow and develop within the intermediate host into a sac-like ...

  5. Sexual reproduction - Wikipedia

    en.wikipedia.org/wiki/Sexual_reproduction

    Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. [6][7] Sexual reproduction also occurs in some unicellular eukaryotes. [2][8] Sexual reproduction does not occur in prokaryotes, unicellular organisms without cell nuclei, such as bacteria and archaea.

  6. Tree of life (biology) - Wikipedia

    en.wikipedia.org/wiki/Tree_of_life_(biology)

    Tree of life (biology) The tree of life or universal tree of life is a metaphor, conceptual model, and research tool used to explore the evolution of life and describe the relationships between organisms, both living and extinct, as described in a famous passage in Charles Darwin 's On the Origin of Species (1859). [1]

  7. Tadpole - Wikipedia

    en.wikipedia.org/wiki/Tadpole

    The life cycle of all amphibians involves a larval stage that is intermediate between embryo and adult. In most cases this larval stage is a limbless free-living organism that has a tail and is referred to as a tadpole, although in a few cases (e.g., in the Breviceps and Probreviceps genera of frogs) direct development occurs in which the ...

  8. Pidyon haben - Wikipedia

    en.wikipedia.org/wiki/Pidyon_haben

    Exodus 13:12–15 The redemption price for firstborn non-Levites was set at 5 shekels : The first [male] issue of the womb of every being, human or beast, that is offered to יהוה, shall be yours; but you shall have the male first-born of human beings redeemed, and you shall also have the firstling of impure animals redeemed.

  9. Biogeochemical cycle - Wikipedia

    en.wikipedia.org/wiki/Biogeochemical_cycle

    A biogeochemical cycle, or more generally a cycle of matter, [1] is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth's crust. Major biogeochemical cycles include the carbon cycle, the nitrogen cycle and the water cycle. In each cycle, the chemical element or molecule is ...