Candy Meiosis

1
Candy Meiosis

• Objective Use candy to make models of cell
  divisions of spermatogenesis oogenesis.

2
Introduction- Cell division

• 1. Mitosis
• Somatic (body) cells
• Identical daughter cells created
• 1 division--gt 2 diploid cells

• 2. Meiosis
• Gametes (sex cells)
• New daughter cells are different from each other
  and the original
• 2 divisions--gt 4 haploid cells

3
Introduction- Meiosis

• Meiosis I
• Chromosomes replicate
• Homologous chromosomes pair up
• Crossing over can occur
• Chromosome number is haploid at end but
  chromosomes are still duplicated (X-shaped)
• Meiosis II
• Just like mitosis
• Sister chromatids separate

4
Introduction- Meiosis

• 1. Spermatogenesis
• Male gametes (pollen, sperm)
• 4 sperm produced
• Equal distribution of cytoplasm and organelles

• 2. Oogenesis
• Female gametes (ova, ovules)
• 1 ovum and 3 polar bodies produced
• egg gets virtually all the cytoplasm organelles

5
(No Transcript)
6
To Do and Notice

1. Pick up a tray. Do not eat the candy until youve
   completed the activity.
2. Use string to create a cell membrane and a
   nuclear envelope.
3. Use 2 colors of gummy worms to make chromosomes
   that are replicated and arranged in homologous
   pairs. Where should they go?
4. Spread the remaining candy around the cytoplasm.
5. Cut the nuclear envelope into 4 pieces and set
   aside.
6. Cut the cell membrane into 2 pieces and form 2
   new circles.

7
To Do and Notice

• 7. Each new cell gets a replicated chromosome.
• 8. Divide the candy appropriately between the 2
  cells depending upon whether you are making eggs
  or sperm.
• 9. Cut the strings again to make 4 cell
  membranes. Where does the candy (organelles
  cytoplasm) go? Separate sister chromatids- one
  per cell.
• 10. Use the 4 pieces of string from the original
  nuclear envelope to make 4 new ones, show me and
  get a stamp in your notebook. Draw yours and
  another teams with the opposite gamete.

8
To Do and Notice

• OK, now you can eat the wrapped candy.
• Clean up by throwing away string and extra candy
  pieces. Put scissors back on the trays and return
  them to the back of the room.