<Table> <Tr> <Td> </Td> <Td> This article's lead section may be too long for the length of the article . Please help by moving some material from it into the body of the article . Please read the layout guide and lead section guidelines to ensure the section will still be inclusive of all essential details . Please discuss this issue on the article's talk page . (March 2018) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article's lead section may be too long for the length of the article . Please help by moving some material from it into the body of the article . Please read the layout guide and lead section guidelines to ensure the section will still be inclusive of all essential details . Please discuss this issue on the article's talk page . (March 2018) </Td> </Tr> <P> Sexual reproduction is a form of reproduction where two gametes fuse together . Each gamete contains half the number of chromosomes of normal cells . They are created by a specialized type of cell division, which only occurs in eukaryotic cells, known as meiosis . The two gametes fuse during fertilization to produce DNA replication and the creation of a single - celled zygote which includes genetic material from both gametes . In a process called genetic recombination, genetic material (DNA) joins up so that homologous chromosome sequences are aligned with each other, and this is followed by exchange of genetic information . Two rounds of cell division then produce four daughter cells with half the number of chromosomes from each original parent cell, and the same number of chromosomes as both parents . For instance, in human reproduction each human cell contains 46 chromosomes in 23 pairs . Meiosis in the parents' gonads produce gamete cells which only contain 23 chromosomes each . When the gametes are combined via sexual intercourse to form a fertilized egg, the resulting child will have 23 chromosomes from each parent genetically recombined into 23 chromosome pairs or 46 total . </P> <P> Cell division mitosis then initiates the development of a new individual organism in multicellular organisms, including animals and plants, for the vast majority of whom this is the primary method of reproduction . </P>

Name the single cell from where life begins in all sexually reproducing organisms