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In species that use the XY sex-determination system, parthenogenetic offspring have two X chromosomes and are female. In species that use the ZW sex-determination system the offspring genotype may be one of ZW (female), [30] [31] ZZ (male), or WW (non-viable in most species, [33] but a fertile, [dubious – discuss] viable female in a few, e.g ...
The biologist Thierry Lodé proposed (2001, 2012) five modes of reproduction based on the relationship between the zygote (fertilised egg) and the parents: [1] [2] Ovuliparity: fertilisation is external, the oocytes being released into the environment and fertilised outside the body by the male. [1]
Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. There are two forms of reproduction: asexual and sexual. In asexual reproduction, an organism can reproduce without the involvement of another organism.
The set of processes included under the term arrhenotoky depends on the author: [1] arrhenotoky may be restricted to the production of males that are haploid (haplodiploidy); may include diploid males that permanently inactivate one set of chromosomes (parahaploidy); or may be used to cover all cases of males being produced by parthenogenesis (including such cases as aphids, where the males ...
A breeding pair of Persian leopards. Breeding pair is a pair of animals which cooperate over time to produce offspring with some form of a bond between the individuals. [1] For example, many birds mate for a breeding season or sometimes for life.
A mule is a sterile hybrid of a male donkey and a female horse.Mules are smaller than horses but stronger than donkeys, making them useful as pack animals.. In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different varieties, subspecies, species or genera through sexual reproduction.
The word is most often used for the offspring of mammals, but can be used for any animal that gives birth to multiple young. In comparison, a group of eggs and the offspring that hatch from them are frequently called a clutch, while young birds are often called a brood. Animals from the same litter are referred to as littermates.
While rare, mostly abortive, parthenogenesis is not unknown in birds and eggs can be diploid, automictic and results in male offspring. [99] Birds are solely gonochoric, [100] meaning they have two sexes: either female or male. The sex of birds is determined by the Z and W sex chromosomes, rather than by the X and Y chromosomes present in mammals.