Meiosis and Sexual Development Topic 8: Giving Life a Helping Hand

Meiosis Videos Meiosis with beads! http://www.youtube.com/watch?v=zGVBAHAsjJM More Meiosis http://www.youtube.com/watch?v=qCLmR9-YY7o October 2013, Cichanowicz

Meiosis The process of cell division that produces 4 genetically different cells. This process occurs for the reproductive cells and takes place in the ovaries or in the testicles. The 4 resultant cells, daughter cells, are all different from the mother cell from which they came. Each cell only contains 23 chromosomes (not paired). They are haploid cells. The function of meiosis is to produce the cells that will unit to form a gamete during sexual reproduction. October 2013, Cichanowicz

Meiosis The mother cell undergoes DNA replication. Crossing over may occur between homologous chromosomes. Two daughter cells (haploid cells) with double chromosomes (X) are formed. The daughter cells divide, without DNA replication, to form four new cells that are genetically different from one another, haploid cells. October 2013, Cichanowicz

Cell Division - Compared Mitosis Meiosis Type of Cell Somatic Cells Functions Growth of cells Repair cells Number of chromosomes in daughter cells 23 pairs of chromosomes Diploid cells Type of Cell Reproductive cells Functions Production of reproductive cells: ova spermatozoa Number of chromosomes in daughter cells 23 chromosomes (not paired) Haploid cells October 2013, Cichanowicz

http://www.youtube.com/watch ?v=BFrVmDgh4v4 Fertilization http://www.youtube.com/watch ?v=BFrVmDgh4v4 One sperm will unite with one ovum during fertilization. The two gametes unite to form a zygote; this is the result of the union of the genetic information from the mother and the father. Fertilization: The fusion of the genetic material from the spermatozoa and the ovum. After fertilization occurs the cells will divide through mitosis over and over again. October 2013, Cichanowicz