ScienceMakers Toolkit Manual - The History Makers

Life Science
Work in cooperative teams of 3 or 4 students. Assign students a position as A, B, C, D. Assign a specifi c task for
A, another task for B, etc. For example:
A constructs Mom
B constructs Dad
C constructs the chromosomes for Mom
D constructs the chromosomes for Dad
A makes Mom’s egg by picking with eyes shut the haploid egg set of chromosomes
B makes Dad’s sperm by picking with eyes shut the haploid sperm set of chromosomes
C constructs the baby
D also constructs a recycle critter (optional). A pure homozygous recessive critter would be interesting to see.
This could be the older sister.
ALL students should do the calculation of the percent probability of the new baby.
Some interesting critters that my students have made include:
• aluminum can worms (Traits include color of can, number of cans, number of ring pull eyes, legs, tail or
proboscis, bumps on skin).
• plastic bottle critters (Traits include arms, legs, hair color, eye color, type of nose, tail, etc.)
• newspaper monsters (Papers are cut, twisted and tied to form various traits)
You may want to restrict them solely to what we recycle, or you may want to allow them to use other miscellaneous
items to create more traits.
Throw in a quick lesson about how fast things biodegrade or the benefi ts of recycling and the world’s garbage
crisis. Newspaper is a wood product and may eventually decay. Tin cans will rust and decay eventually. Aluminum
will be next and will weaken and decay (but as an un-mineable source in a landfi ll). Plastic bottles will last
forever and not decay; they are photo-sensitive, it may break down in the presence of light but will remain as
small plastic beads in the soil or water supply. (What harm will this do?) Glass will not decay.
Punnett Square Method
1. Create a key box:
• Write down the inherited traits and their dominant and recessive genotypes and phenotypes.
• Use a different letter of the alphabet or symbol for each trait.
2. Write the phenotypic parental cross. (ie, verbally write what the problem said is to be crossed.)
3. Write the genotypic parental cross.
4. Translate the parents’ phenotypes into the respective genotypes. (ie, write the symbols that fi t the
phenotype given, remembering that the organism is diploid and has 2 alleles/letters for each inherited
trait.)
5. On the side, calculate the number of squares needed in the Punnett Square by the formula 4n, where n =
number of traits in the problem (number of different letters of the alphabet).
6. Figure out all possible gametes (egg or sperm) that could be formed by meiosis for that parent. What are
all the possible ways you could combine the alleles and in each case have the haploid combination,
such that you have 1 allele/letter for each inherited trait? The number of possibilities will equal the
number of squares down one side. Note: Some problems just ask for gamete possibilities and not for
fi nal ratios of the offspring, in which case this would be the last step.
7. Draw the squares and write in the gametes by putting the female gametes (eggs) on one side (the top,
say) and the male gametes (sperm) on the other side (the left, say).
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