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  2. Animal embryonic development - Wikipedia

    en.wikipedia.org/wiki/Animal_embryonic_development

    The egg cell is generally asymmetric, having an animal pole (future ectoderm).It is covered with protective envelopes, with different layers. The first envelope – the one in contact with the membrane of the egg – is made of glycoproteins and is known as the vitelline membrane (zona pellucida in mammals).

  3. Oviparity - Wikipedia

    en.wikipedia.org/wiki/Oviparity

    The traditional modes of reproduction include oviparity, taken to be the ancestral condition, traditionally where either unfertilised oocytes or fertilised eggs are spawned, and viviparity traditionally including any mechanism where young are born live, or where the development of the young is supported by either parent in or on any part of their body.

  4. Fertilisation - Wikipedia

    en.wikipedia.org/wiki/Fertilisation

    Oviparous animals laying eggs with thick calcium shells, such as chickens, or thick leathery shells generally reproduce via internal fertilisation so that the sperm fertilises the egg without having to pass through the thick, protective, tertiary layer of the egg. Ovoviviparous and viviparous animals also use internal fertilisation.

  5. Modes of reproduction - Wikipedia

    en.wikipedia.org/wiki/Modes_of_reproduction

    The three traditional modes of reproduction are: [1] Oviparity, taken to be the ancestral condition, where either unfertilised oocytes or fertilised eggs are spawned. [1] Viviparity, including any mechanism where young are born live, or where the development of the young is supported by either parent in or on any part of their body. [1]

  6. Estrous cycle - Wikipedia

    en.wikipedia.org/wiki/Estrous_cycle

    Some species, such as cats, cows and domestic pigs, are polyestrous, meaning that they can go into heat several times per year. Seasonally polyestrous animals or seasonal breeders have more than one estrous cycle during a specific time of the year and can be divided into short-day and long-day breeders:

  7. Internal fertilization - Wikipedia

    en.wikipedia.org/wiki/Internal_fertilization

    Most birds do not have penises, but achieve internal fertilization via cloacal contact (or "cloaca kiss"). In these birds, males and females contact their cloacas together, typically briefly, and transfer sperm to the female. However, water fowls such as ducks and geese have penises and are able to use them for internal fertilization.

  8. Mating - Wikipedia

    en.wikipedia.org/wiki/Mating

    In some birds, it includes behaviors such as nest-building and feeding offspring. The human practice of mating and artificially inseminating domesticated animals is part of animal husbandry . In some terrestrial arthropods , including insects representing basal (primitive) phylogenetic clades, the male deposits spermatozoa on the substrate ...

  9. List of domesticated animals - Wikipedia

    en.wikipedia.org/wiki/List_of_domesticated_animals

    2g Other birds: Tawny owl (Strix aluco) [100] date uncertain Europe (including the United Kingdom) pest control, show, pets 2g Other birds: Puna ibis (Plegadis ridgwayi) date uncertain Peru: meat, eggs, pest control 2g Other birds: Celebes warty pig (Sus celebensis) [101] date uncertain Sulawesi: meat, tusks, pets Historically farmed 1a ...