History of 2.1 Apk

Organisms of many species are specialized into male and female varieties, each known as a .[1][2] ual reproduction involves the combining and mixing of genetic traits: specialized cells known as gametes combine to form offspring that inherit traits from each parent. The gametes produced by an organism define its : males produce small gametes (e.g. spermatozoa, or sperm, in animals) while females produce large gametes (ova, or egg cells). Individual organisms which produce both male and female gametes are termed hermaphroditic.[2] 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 es of an organism; these ual dimorphisms can reflect the different reproductive pressures the es experience. For instance, mate choice and ual selection can accelerate the evolution of physical differences between the es.

Among humans and other mammals, males typically carry an X and a Y chromosome (XY), whereas females typically carry two X chromosomes (XX), which are a part of the XY -determination system. Humans may also be inter. Other animals have various -determination systems, such as the ZW system in birds, the X0 system in insects, and various environmental systems, for example in reptiles and crustaceans. Fungi may also have more complex allelic mating systems, with es not accurately described as male, female, or hermaphroditic.

This app is about history and for research Purpose .