Gamete is a cell that fuses with another cell during fertilization (conception) in organisms that reproduce sexually. In species which produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual which produces the larger type of gamete called an ovum (or egg) and a male produces the smaller tadpole-like type called sperm. This is an example of anisogamy or heterogamy, females and males condition that produce gametes of different sizes (this is the case in humans, the human egg is about 20 times greater than the human sperm). In contrast, the state is isogamy gametes of both sexes with the same size and shape, and as arbitrary designators for the mating type. The name gamete was introduced by the Austrian biologist Gregor Mendel. Gamete carry genetic information for half of an individual, 1N each type.

Sperm-egg distinction

The eggs are relatively few, large, and do not move, while the sperm are many small, movable. The size difference is largely (but not fully) accounted for very large egg cytoplasm. Eggs awaiting zygote formation may be anchored or something in the environment or by a body that contains, sperm may depend exclusively on its own or motility can be relayed in place by a body such as the pollen to reach the place of formation of zygote. Typically more than sperm eggs are created and wasted, never to a gamete fusion partner.

The distinction sperm egg is the basis for distinguishing between males and females. Since some algae and fungi have mating by combining two identical gametes, no distinction male / female in these species. This raises the question of why the great majority of species / families reproduce by sperm and egg. One theory of why the male / female distinction is so common is that he facilitated a meeting between gametes in marine species ancestor.

Dissimilarity

In contrast to a gamete, the diploid somatic cells of an individual contains one copy of chromosome set from the sperm, and one copy of chromosome set from the egg, that is, the cells of the offspring have characteristics of both genes from the parent and mother. The chromosomes of the gametes are not exact copies of any one set of chromosomes carried in the somatic cells of the individual who produced the gametes. They can be produced by hybrids crossover (a form of genetic recombination) chromosome which occurs at meiosis. This hybridization has a random element, and the chromosomes tend to be somewhat different in every gamete an individual produces. Furthermore, base pairs in chromosomes often undergo random mutations, resulting in modified DNA (and subsequently new proteins and phenotypes). This mutation, recombination, and the fact that the two chromosome sets ultimately come from a grandmother or a grandfather on each parental side account for the genetic dissimilarity of siblings.

Plants

Plants that reproduce sexually also have gametes, however, they are produced in the anther and ovary. They produce pollen and eggs by meiosis in a manner similar to animals.

Sex determination

In humans, an egg can carry only one X chromosome (the X and Y), while the sperm can take an X or Y, so the male sperm determines the sex of any resulting zygote, the zygote has two X chromosomes it will evolve into a woman, if she has one X and one Y chromosome, which will develop into a male. For birds, the female egg determines the sex of the offspring through the ZW sex determination system.

Note:
There is some research that indicates that it is the egg that allows the sperm to enter, so choose which sperm fertilizes it. Thus, even if the sperm is the carrier or of X, X or X, Y, which may be indeed the case that the egg is to choose the gamete sex, defining which the sperm are included.