Gametes can be identical in form and function (known as isogamy), but, in many cases, an asymmetry has evolved such that two different types of gametes (heterogametes) exist (known as anisogamy).
Physical differences are often associated with the different sexes of an organism; these sexual dimorphisms can reflect the different reproductive pressures the sexes experience.
However, no third gamete type is known in multicellular plants or animals.
the origin of chromosomal sex determination may have been fairly early in eukaryotes (see evolution of anisogamy).
Sexual reproduction is a process specific to eukaryotes, organisms whose cells contain a nucleus and mitochondria.
Life has evolved from simple stages to more complex ones, and so have the reproduction mechanisms.on the net and you won't have a problem finding whatever you're after as it has tons of hot various categories.Azeri chat sayt Ehtirasli chat, Ehtirasli sayt, Erotik chat, Erotik sayt, Seksi chat, Seksi sayt, Ehtirasli Cat, Seksi Cat, Azeri sayt, chat tanisliq, Real Tanisliq, MP3 Axtar, Pulsuz yukle, Seksi Yukle, Seksleri MYCHAT.These gametes are the cells that are prepared for the sexual reproduction of the organism.Sex comprises the arrangements that enable sexual reproduction, and has evolved alongside the reproduction system, starting with similar gametes (isogamy) and progressing to systems that have different gamete types, such as those involving a large female gamete (ovum) and a small male gamete (sperm).In complex organisms, the sex organs are the parts that are involved in the production and exchange of gametes in sexual reproduction.Many species, both plants and animals, have sexual specialization, and their populations are divided into male and female individuals.Other animals have different sex-determination systems, such as the ZW system in birds, the X0 system in insects, and various environmental systems, for example in crustaceans.Fungi may also have more complex allelic mating systems, with sexes not accurately described as male, female, or hermaphroditic.spermatozoa, or sperm, in animals; pollen in seed plants) while females produce large gametes (ova, or egg cells).Individual organisms which produce both male and female gametes are termed hermaphroditic.