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The male parent of a horse, a stallion, is commonly known as the sire and the female parent, the mare, is called the dam. [1] Both are genetically important, as each parent genes can be existent with a 50% probability in the foal. Contrary to popular misuse, "colt" refers to a young male horse only; "filly" is a young female.
The mule is a domestic equine hybrid between a donkey and a horse.It is the offspring of a male donkey (a jack) and a female horse (a mare). [1] [2] The horse and the donkey are different species, with different numbers of chromosomes; of the two possible first-generation hybrids between them, the mule is easier to obtain and more common than the hinny, which is the offspring of a male horse ...
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.
Ovo-viviparity: or oviparity with retention of zygotes in either the female's or in the male's body, but there are no trophic interactions between zygote and parents. [1] This mode is found in the slowworm, Anguis fragilis. In the sea horse, zygotes are retained in the male's ventral "marsupium".
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.
Anisogamy is the form of sexual reproduction that involves the union or fusion of two gametes which differ in size and/or form. [12] The smaller gamete is considered to be male (a sperm cell), whereas the larger gamete is regarded as female (typically an egg cell, if non-motile).
Female mate choice, which gives the female the ability to choose her partner before and after mating. The female cannot do this with external fertilization because she may have limited control of who is fertilizing her eggs, and when they are being fertilized. [1] Making a decision for the conditions of reproduction, like location and time. [22]
This is quite different from the normal polyspermy block on the outside of the egg. [16] Even though multiple sperm enter the cell and each form an aster (see: Fertilisation § The sperm aster and zygote centrosomes ), only one male pronucleus is chosen to merge with the female pronucleus.