Sperm and egg formation in terms of ploidy

Course Outline

A.  Sperm formation

B.  Egg Formation

C. Fertilization

     1.  Gametes

      2. Ploidy

          a.  haploid

          b.  diploid

          c.  polyploid

           d.  aneuploid

Teaching Aids 

1. Computer

2. Smart Board

3. Power Point

 4. Definition sheet for the student to fill out for the following vocabulary: gametes, haploid, fertilization, diploid, polyploidy, aneuploidy, and the symbol n.

5. Students are to explain in a paragraph the reduction in chromosome number that occurs during meiosis.

Class Project

Students are to draw on a posterboard process that changes the chromosome number.  The poster must include the male and female diagrams and gamete formation with reduction division included.

Review Questions

1.  When two cells with n number of chromosomes fuse, what type of cell results?

2.  During which processes are gametes formed?

3.  What process results in an exchange of genes between homologous chromosomes?

4.  How many chromosomes would a cell have during metaphase I of meiosis if it had 12 chromosomes during interphase?

    a.  6                                   c.  24

    b.  12                                 d.  36

5.  A horse has 64 chromosomes and a donkey has 62.  Using your knowledge of meiosis, evaltuate why a cross between a horse and donkey produces a mule, which usually is sterile.

6.  In bees, the female queen bee is diploid but male bees are haploid.  The fertilized eggs develop into female bees and the unfertilized eggs develop into males.  How might gamete production in male bees differ from normal meiosis?


Some good information can be found at this website about ploidy.  http://www2.estrellamountain.edu/faculty/farabee/biobk/biobookmeiosis.html

Ploidy is also addressed nicely in this meiosis tutorial at this site http://www.biology.arizona.edu/cell_bio/tutorials/meiosis/page2.html

Other Useful Information

Students will write a report on polyploidy and explain what advantages or disadvantages are caused by it.