2Sexual Reproduction Diploid Cell A cell that has chromosomes located in similar pairs.These cells are called body cells.In humans, body cells have 23 pairs of chromosomes (46 total chromosomes).
3Sexual Reproduction Haploid Cell Chromosomes are not located in pairs. Only have half of the number of chromosomes as a body cell.These cells are called sex cells.In humans, sex cells have 23 chromosomes.
4Sexual Reproduction Fertilization Occurs when a sperm cell joins with an egg cell to create a zygote.The sperm and egg cells are haploid cells.The resulting zygote is diploid.
5Meiosis and Sex Cells Meiosis Process that divides one diploid cell into four haploid cells.Broken into Meiosis I and Meiosis II.
6Meiosis and Sex Cells Why is meiosis important? Ensures that sex cells are only haploid so that when they are joined they form a diploid zygote.
7Meiosis IProphase IChromosomes copied before meiosis begins are visible as two chromatids.Each chromatid pair links with its similar set of chromatids to form a tetrad.
23Summary of Meiosis Meiosis - Briefly Meiosis I Meiosis II Starts with one diploid cellForms two cellsMeiosis IIEach of the two cells formed in meiosis I forms two cellsEnd result is four haploid sex cells
24Mistakes in Meiosis Possible mistakes: Haploid cells may end up with too few or too many chromosomes.Zygotes formed from these cells may die or have deformations.