High School SMILE Meeting
13 March 2001
Notes Prepared by Porter Johnson


Karlene Joseph (Lane Tech HS) Handout: Genetic Recombination
directed activities that review meiosis and genetics by employing small stackable block cubes [similar to LEGOTM blocks]. We used 6 cubes for each of 6 different colors, and connected 3 cubes of the same color to represent chromosomes. Then we constructed an original parent cell by placing one chromosome of each color in a matrix of 3 pairs of "homologous" chromosomes, and assigned letters [alleles] to each color; [eg a, b, c, A, B, C]. Capital letters represent the dominant genes, and lower case letters represent recessive genes. We then simulated the following rearrangements.

We indicated the dominant genes for each case.

Here is a list of human traits for which there are contrasting forms.  Within each trait one form (eg oval versus round head shape) was arbitrarily chosen as dominant and the other recessive.  The results of each person's "virtual offspring" (above) could then be converted into a "phenotype" by making interesting and usually humorous sketches of the faces.

1Head shapeOval vs Round
2Chin shapePointed vs Square
3Eye shapeRound vs Almond shaped
4Hair shapeCurly vs Straight
5Nose sizeBig vs Little
6Ear sizeBig vs Little
7EarlobesLarge hanging vs Small attached
8EyebrowsBushy vs Thin
9LipsThick vs Thin

Sarah Brennan (Robeson HS) Handout: Stoichiometry Fudge Recipe
presented us with a fudge recipe consisting of powdered sugar, cocoa, butter, milk, vanilla. For one batch, here is a recipe that gives the amounts of ingredients required and the amount of fudge produced.

Ingredient:Powdered SugarCocoaButter MilkVanillaFudge
Recipe3 2/3 cup 1/2 cup 1/2 cup 1/4 cup 1 teaspoon 48 pieces
If we had only 1/4 cup of butter, we would scale this recipe down by a factor of 2:

Ingredient:Pwdr SugarCocoaButter MilkVanillaFudge
#11 5/6 cup 1/4 cup 1/4 cup 1/8 cup 1/2 teaspoon 24 pieces
Now, supoose we had only 3 cups of sugar. We would multiply each of the amounts by the factor 3 / (3 2/3)= 9/11 to obtain

Ingredient:Pwdr SugarCocoaButter MilkVanillaFudge
#23 cup 0.4 cup 0.4 cup 0.20 cup0.8 teaspoon 39 pieces
Every good cook knows how to scale the proportions to vary the size of each batch. For Example, what are the other proportions if 5 cups of sugar are available. Simple; you just multiply by 5 / (3 2/3) =15 /11. The results:

Ingredient:Pwdr SugarCocoaButter MilkVanillaFudge
#35 cup 0.7 cup 0.7 cup 1/3 cup 1 1/3 teaspoon 65 pieces

The principles of stoichiometry are identical to those of the culinary arts. Once you find the right proportions, you simply scale the amounts of ingredients to make the right size batch. For example, consider the reaction

2 H2 + O2 ---> 2 H2O
That is, two molecules of H2 and one molecule of O2 are required to make two molecules of H2O. We can go from molecules to moles to grams just by using the molecular weights of the ingredients:

Mol Wt
2 gr/mole
32 gr/mole
18 gr/mole
#12 molecules1 molecule 2 molecules
#22 moles1 mole2 moles
#34 grams32 grams 36 grams

Zoris Soderberg (Webster School) Introduction to Nutrition

Part A:
She asked the question Where does your food come from? Do you like hot dogs, ham sandwiches, pork chops, or ribs?

She drew a picture of a pig, and marked these three regions

RegionFood Product
Hips and thighsHam
Under bellyRibs
Top: backbonePork chops
[The rest of the pig gets ground up to make hot dogs!]

Zoris then took a bag of FritosTM corn chops and read these ingredients on the list:

Rates of diabetes and obesity are soaring among children as well as adults, and increasing levels of "fast food" intake are surely the cause. We should limit our intake of these "empty calorie" foods. Read the label; set a better table!

Part B:
Zoris then handed out small [40 ml] new medicine bottles, which she got from a druggist. [Do not use old medicine bottles for this purpose!] Each bottle was half-full with an opaque liquid. We shook them vigorously until a watery substance separated from a solid residue. We had just made butter from cream. The whole process took about 5 minutes. We enjoyed spreading the butter on saltine crackers and eating. It was great!

Notes taken by Ben Stark and Karlene Joseph