Transcript candy meiosis

Candy Meiosis
Objective: Use candy to make models of
cell divisions of spermatogenesis &
oogenesis.
Introduction- Cell division
1. Mitosis
• Somatic (body)
cells
• Identical daughter
cells created
• 1 division--> 2
diploid cells (46
chromosomes)
2. Meiosis
• Gametes (sex cells)
• New daughter cells
are different from
each other and the
original
• 2 divisions--> 4
haploid cells (23
chromosomes)
Introduction- Meiosis
Meiosis I
• Chromosomes replicate
(briefly quadraploid)
• 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
Introduction- Meiosis
1. Spermatogenesis
2. Oogenesis
•
• Female sex cells (ova,
ovules)
• 1 ovum and 3 polar
bodies produced
• egg gets virtually all the
cytoplasm & organelles
•
•
Male sex cells
(pollen/sperm)
4 sperm produced
Equal distribution of
cytoplasm and
organelles
New input page
 Title: Candy Meiosis
 Divide into 4 panels
 Label panels “beginning”, “after meiosis 1”, “after meiosis
2 sperm”, “after meiosis 2 egg”
 As you proceed following teacher directions, draw results
in each panel.
 Label chromosomes, organelles, diploid cell, haploid cell
 OUTPUT page tonight: compare/contrast
spermatogenesis & oogenesis via paragraph, venn
diagram or concept map
To Do and Notice
1. Pick up a tray. Do not eat the candy until you’ve
completed the activity.
2. Use string to create a cell membrane and a nuclear
envelope.
3. Use 2 colors of gummy worm 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. For oogenesis, uneven sizes, for
spermatogenesis, equal sizes
To Do and Notice
7. Each new cell gets a replicated chromosome
(gummy worm X). What has happened to the
amount of genetic material in each cell?
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) go? Separate
sister chromatids- one per cell.
10. Show me the final product, after you use the
pieces of the original nuclear envelope to make 4
new ones and get a stamp in your notebook.
To Do and Notice
 OK, now you can eat the 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.