Sexual reproduction

Sexual reproduction is a process where organisms form offspring that combine genetic traits from both parents.[1] Genetic traits are contained within the DNA of chromosomes — by combining a set of chromosomes from each parent, an organism is formed containing a doubled set of chromosomes. This double-chromosome stage is called "diploid", while the single chromosome stage is "haploid". Diploid organisms can, in turn, form haploid cells that randomly inherit one of the two different chromosomes, a process called meiosis.[2] Meiosis also involves a stage of chromosomal crossover, in which regions of DNA are exchanged between the two chromosomes to form a new pair of mixed chromosomes. These processes result in the recombining of different genetic traits.
In many organisms the haploid stage has been reduced to specialized cells called gametes specialized to recombine and form a new diploid organism. Sometimes gametes are externally similar, particularly in size (isogamy); often, however, an asymmetry has evolved such that the gametes are different in size and other aspects (anisogamy).[3] By convention, the larger gamete (called an egg cell or ovum) is considered female, while the smaller gamete (called a sperm) is considered male. An individual that produces exclusively large gametes is female, and one that produces exclusively small gametes is male. An individual that produces both types of gametes is a hermaphrodite; in many cases hermaphrodites are able to self-fertilize and produce offspring on their own, without a second organism
http://en.wikipedia.org/wiki/Image:Sexual_cycle.svg#file