Name:______________________________________

Penny Flip Genetics LabMaterials: 2 pennies, chart on human traits

Pre Lab:Both you and your partner will be heterozygous for all traits. Draw a Punnett Square showing this cross and give me the phenotypic and genotypic %:

Phenotypic %:

_____ Dominant : _____ Recessive

Genotypic %:

______ AA : _______ Aa : ______ aa

Now assume you are looking at incompletely dominant traits. Again, both you and your partner will be heterozygous for all traits. Draw a Punnett Square showing this cross and give me the phenotypic and genotypic %:

Phenotypic %:

_____ Dom : _____ Intermediate: _____ : Rec

Genotypic %:

______ AA : _______ Aa : ______ aa

Purpose: The purpose of this lab is to see if your class can generate offspring phenotypic and genotypic ratios (dependent) that match those you just figured out above by flipping a coin to represent the donation of alleles from parents to offspring (independent).

Hypothesis:

_____________________________________________________________________________________________________________________________________________________________________________________________________________________

Procedure:

Single Allele Traits1. Determine which partner will toss for the male and which will toss for the female. Each of you will get a penny.

2. Have the partner who is representing the male flip the coin, if the coin lands heads up, the offspring is female, if tails, then the offspring is male. What sex is your offspring?

________________

3. For all coin tosses from now on, heads will represent the dominant allele and tails will represent the recessive allele. For each trait on the charts on the next two pages, you and your partner will flip your coins to determine the GENOTYPE of your offspring. Put a check in the box that represents your offspring's appearance, or PHENOTYPE.

Example: For the shape of the face, your partner tossed heads and you tossed tails. This means the offspring's genotype is Rr and the child will have a round face, so check that box. If you had both tossed tails, you would check the square-shaped face (rr) and if you had both tossed heads, you would have a round shaped face (RR)

4. List the traits in the space below indicating if they showed normal dominance, or incomplete dominance:

Traits showing normal dominance: Traits showing incomplete dominance:-shape of face -hair

Polygenic Traits - Hair, Eye, SkinSome traits are controlled by more than two genes, such as hair color, eye color and skin color. For these traits you will need to perform a different procedure to determine your offspring's phenotype.

Hair color

Dark hair is dominant over light. To determine the color of the offspring’s hair, assume there are two gene pairs involved (there are actually probably more than that, but for the purpose of this activity, let’s not go crazy). Flip your coin first to determine the genotype of the first pair of alleles (AA, Aa,

or aa). Now, flip the coins again to determine the genotype of the second pair of alleles (BB, Bb, or bb). Match the genotype you have to the hair color on the chart. Circle your offspring’s hair color.

If the genotype is.... The hair color is....AABB blackAABb blackAAbb redAaBB brownAabb regular blondeAaBb brownaaBB dark blondeaaBb regular blondeaabb pale yellow blond

Skin Color

Skin color is controlled by a lot of different genes that basically add together to determine how dark the skin is and variations in tone. To simulate how skin color might be determined flip a single coin 10 times. Each time the coin turns up heads, give your offspring a point. Add your points together. 10 pts would be a very dark child and 1 pt would be a very

pale child. How many points does your child have? __________

Eye Color

Dark eyes are dominant over light. To determine the color of the offspring’s eyes, assume there are two gene pairs involved, one which codes for depositing pigment in the front of the iris, and one which codes for depositing pigment in the back of the iris. Determine the genotype of the first pair (AA, Aa, or aa) Then flip again to determine the genotype of the second pair (BB, Bb, or bb). Use the chart below to find out what eye color your offspring has and circle it.

If the genotype is.... The hair color is....

AABB dark brownAABb dark brownAAbb brown

AaBB brown with green flecks

Aabb brownAaBb grayaaBB greenaaBb dark blueaabb light blueYour data:

Trait: Phenotype: GenotypeSex:Shape of face:Cleft in chin:Hair:Widow’s Peak:Spacing of eyes:Shape of eyes:Position of eyes:Size of eyes:Length of eyelashes:Shape of eyebrows:Position of eyebrows:Size of nose:Shape of lips:Size of mouth:Size of ears:Freckles:Dimples:HairSkinEyes

Scientific Drawing: Now that you have determined all the traits of your child. You will draw a picture. Use colors and try to make the sketch as accurate as possible given the traits your child inherited. Make sure you name your child too! This drawing should be included on your lab report.

Class Data:

Total number of babies in class: ______

1. 2. 3. 4. 5.# of

babies# from column

1/total # of babies

# from column 2 *100 (%)

Expected % (see pre-lab)

Do the % in column 3

and 4 match up?

MaleFemaleRound FaceSquare faceNo cleft chinCleft chinCurly HairWavy HairStraight hairWidow’s peakNo widow’s peakClose eye spacingNormal eye spacingFar eye spacingAlmond eye spacingRound eye spacingStraight eye positionSlanted eye positionLarge eyesMedium eyes

Small eyes1. 2. 3. 4. 5.

Data continued

# of babies

# from column

1/total # of babies

# from column 2 *100 (%)

Expected % (see pre-lab)

Do the % in column 3

and 4 match up?

Long eyelashes

Short eyelashes

Bushy eyebrows

Thin eyebrows

Not connected eyebrowsConnected eyebrows

Large noseMedium

noseSmall noseLarge lipsMedium

lipsSmall lips

Large mouth

Medium mouthSmall mouth

Large earsMedium

earsSmall earsFreckles

No frecklesDimples

No dimples

Analysis and ConclusionsGraph:

You will have two graphs. The first will be a bar graph comparing all the traits that show normal dominance. Count up the total number of offspring showing a dominant trait and have that be one bar, have the other bar be the total number of offspring showing the recessive trait.

Next, have a line graph showing the results for the traits displaying incomplete dominance. Count up the number of offspring who were homozygous dominant, and have that be the first point on your line. Next, count up the number of offspring showing the intermediate phenotype and have that be your next point. Finally, count up the number of offspring who were homozygous recessive, and have that be your final point.

Questions:

1. Was your child exactly like any other child in the room? What do you think the odds were that two children in the room would turn out exactly alike?

 

2. How might it be possible for you to show a trait that neither of your parents have?

 

Questions continued: 

3. Why did you have to flip the coin twice to determine hair and eye color?

4. Look at column 5 of your table. How well did the classes data match up with the predicted results? What changes to the procedure could we do to help improve the results of this experiment?

 

 

5. Look at your two graphs. Do graphs make sense based off the predicted results? Explain.

 

Conclusion (address each part with at least one complete sentence)

-Restate the question (see your problem)-Answer the question-Cite evidence from the lab/data to support your answer.-Sources of error? What can be done to improve your experiment? (see analysis question 4)-Apply what you learned to the real world. (How does it relate to real life? How can you or other scientists use this information?)