View source for Gametes

A Gamete is a [[Haploid|haploid]] (1n) cell that when fused with another gamete cell during fertilisation becomes a [[Diploid|diploid]] (2n) cell in [[Organism|organisms]] that reproduce sexually. Gametes will carry half the genetic information of that person.&nbsp;Each sex produces one type of gamete, in humans the male gamete is the [[Sperm cell|sperm cell]] which is much smaller than the female gamete the [[Ovum|ovum]]. These [[Cell|cells]] will be composed of 22 different [[Autosomal chromosomes|autosomal chromosomes]] and one [[Sex chromosome|sex determining chromosome]], either [[X chromosome|X]] (ovum and sperm cell) or [[Y chromosome|Y]] (sperm cell only). If the [[Zygote|zygote]] inherits two [[X chromosome|X chromosomes]] then it will be female, if it inherits an X and a Y then it will be male. 

Gametes are developed by the process of [[Meiosis|meiosis]] in germ cell lines.&nbsp;Sperm cells are produced by [[Spermatogenesis|spermatogenesis]] whilst ovum cells first divide in the embryo but stop at [[Prophase|prophase 1]]. [[Meiosis|Meiosis]] recomences prior to [[Ovulation|ovulation]].&nbsp;&nbsp;&nbsp; 

When meiosis in [[Germ cell|germ cell]] lines goes wrong and nondisjunction occurs the results are [[Aneuploid gametes|aneuploid gametes]], which means the gamete cells have incorrect chromosome numbers, whether it be for autosomal or sex chromosomes. When it occurs for autosomal chromosomes the zygote can be either monosomic (have one of the required chromosomes) or trisomic (have an extra chromosome). One example of autosomal [https://bms.ncl.ac.uk/wiki/index.php/Trisomy trisomy] is [[Down Syndrome|Down Syndrome]], which is the presence of an extra [[Chromosome 21|chromosome 21]]. &nbsp;