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Usually, eggs are laid only by the queen, but the unmated workers may also lay haploid, male eggs either regularly (e.g. stingless bees) or under special circumstances. An example of non-viable parthenogenesis is common among domesticated honey bees. The queen bee is the only fertile female in the hive; if she dies without the possibility of a ...
Scientists believe that an unfertilized egg began to self-divide but then had some (but not all) of its cells fertilized by a sperm cell; this must have happened early in development, as self-activated eggs quickly lose their ability to be fertilized. The unfertilized cells eventually duplicated their DNA, boosting their chromosomes to 46.
While a single specific cause is unknown, chronic egg laying is believed to be triggered by hormonal imbalances influenced by a series of external factors. [1] As in the domestic chicken, female parrots are capable of producing eggs without the involvement of a male – it is a biological process that may be triggered by environmental cues such as day length (days becoming longer, indicating ...
Bird eggs are laid by the females and range in quantity from one (as in condors) to up to seventeen (the grey partridge). Clutch size may vary latitudinally within a ...
The egg is not retained in the body for most of the period of development of the embryo within the egg, which is the main distinction between oviparity and ovoviviparity. [1] Oviparity occurs in all birds, most reptiles, some fishes, and most arthropods. Among mammals, monotremes (four species of echidna, and the platypus) are uniquely oviparous.
In the most commonly used sense of the term, arrhenotoky is synonymous with haploid arrhenotoky or haplodiploidy: the production of haploid males from unfertilized eggs in insects having a haplodiploid sex-determination system. Males are produced parthenogenetically, while diploid females are usually [a] produced biparentally from fertilized eggs.
A yolkless egg is most often a pullet's first egg, produced before her laying mechanism is fully ready. In a mature hen, a yolkless egg is unlikely, but can occur if a bit of reproductive tissue breaks away, stimulating the egg-producing glands to treat it as a yolk and wrap it in albumen, membranes and a shell as it travels through the egg tube.
A trophic egg is an egg whose function is not reproduction but nutrition; in essence, the trophic egg serves as food for offspring hatched from viable eggs. In most species that produce them, a trophic egg is usually an unfertilised egg.