2 Sexual 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).
3 Sexual 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.
4 Sexual 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.
5 Meiosis and Sex Cells Meiosis Process that divides one diploid cell into four haploid cells.Broken into Meiosis I and Meiosis II.
6 Meiosis 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.
7 Meiosis 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.
23 Summary 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
24 Mistakes 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.