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

2. Meiosis Videos Meiosis with beads!
More Meiosis
October 2013, Cichanowicz

3. 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

4. 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

5. 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

6. http://www.youtube.com/watch ?v=BFrVmDgh4v4
Fertilization
?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