Student Name:  _______________________________________________

Write your name on the line above.
The purpose of this task is to observe and analyze the effects of genetics in people. You will have a total of 45 minutes to complete the task. You may use up to 20 minutes to complete the group work. When your group is finished with the group work, one member of the group should tell the facilitator that you have finished. Then you may go on to the individual work and answer questions 2 through 6. You may not talk while you are working on those items.

You and your partner should have the following materials:

• 2 sets of alleles
  
• cup
  
• calculator
  
• pencils

The test faciliator has assigned you a partner to work with during the first part of this task. You will be analyzing genetic probability by assessing some common inherited and observable traits that you both possess. You will then investigate genetic inheritance by analyzing how selected traits exhibited by you and your partner could be passed on to an offspring.

For each trait described on the Information Sheet, you and your partner will record your observations in the table for item number 1. Your information Sheet also contains a review of the genetics information you need to consider for this task. Review the Information Sheet carefully. Then complete the activity for item number 1 with your partner.

• Your body contains a pair of genes for each of the traits you will examine. The two genes found in your body are called your genotype. When working with genetics, your genotype is represented by two letters (e.g., Dd).

• The way you look is determined by the action of the genes in your body. This outward appearance of your genes is called your phenotype. When working with genetics, your phenotype is described by how you look (e.g., you have dimples or you don't have dimples).

• Dominant genes, when present in the body, always show up in your phenotype. It doesn't matter if one or both genes are dominant; one dominant gene will show the presence of that trait in the phenotype. Dominant genes are represented by a capital letter (e.g., D).

• Recessive genes, when present in the body, only show up in your phenotype if both of the pair of genes for that trait are recessive. If there is a dominant gene present, then it hides the recessive gene and the recessive gene is usually inactive. Recessive genes are represented by a lower case letter (e.g., d).

• A hybrid, or heterozygous condition exists when a dominant and a recessive genes are both present in the genotype. The phenotype of a hybrid shows the dominant condition. The hybrid genotype is represented by a capital letter and a lower case letter (e.g., Dd).

• Alleles are different forms of the same gene. For example, there are three alleles for blood type: allele A, allele B, and allele O.

• During reproduction a child receives one gene of the pair from the mother and the other gene of the pair from the father.

• An example of how you will work with this information is shown below. In this example, the trait of dimples is examined.

Kentucky Department of Education
Performance Events 1993-94

1. FOR EACH OF THE TEN TRAITS LISTED BELOW, FOLLOW THESE STEPS. "Length of eyelashes" is used as an example to help you complete the first row of the tables.
   1. Student #1 and Student #2 must determine their genotypes for "length of eyelashes," based on their phenotypes. IMPORTANT! When a person displays a dominant trait, it is often impossible to know, by observing physical characteristics, whether that person's genotype is pure dominant (DD) or hybrid (Dd). So, for the purpose of this task, if you cannot determine whether your genotype is DD or Dd, then record the genotype of dominant physical characteristics as hybrid (Dd). (E.g., if you observe that you have long eyelashes, record your genotype as Dd.) Record the genotypes for Student #1 and Student # 2 in the appropriate columns.

   2. Student #1 will select a set of two round alleles (DD, Dd, or dd) representing his/her geneotype for "lenght of eyelashes," and place them in the cup. Student #2 will place two square alleles that represent his/her genotype for the same trait in the cup.

   3. Shake the cup and then, without looking, remove one round allele and one square allele from the cup. These two alleles will represent a hypothetical genotype resulting from the crossing of these genetic make-ups. Record the genotype in the column labeled "Genotype Resulting from Cross."

   4. Determine and record the appropriate phenotype in the column labeled "Phenotype Resulting from Cross."

   5. Repeat these steps nine more times and complete the data for each trait listed.

   Trait	Genotype- Student #1	Genotype- Student #2	Genotype Resulting from Cross	Phenotype Resulting from Cross
   1. Length of eyelashes
   2. Hair
   3. Size of eyes
   4. Size of mouth
   5. Size of ears
   6. Shape of lips
   7. Shape of eyebrows
   8. Position of eyebrows
   9. Size of nose
   10. Shape of eyes

   When you are finished with the work on this page, tell the facilitator that your pair has finished its work. Then do the individual work. You must work alone on those pages. you may not discuss the questions or share information.

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2. Discuss the accuracy of predicting the appearance of a child based on studying the phenotype of the parents.
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3. Explain the advantage of comparing inheritance patterns based on observing characteristics of a large group of people rather than observing a pair, as you just did.
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4. Describe patterns of inheritance you can see based upon the data you collected on page 4.
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5. Discuss any advantage the traits listed in the table on page 4 might have had that helped people survive in different climates.
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6. Explain, in detail, the various factors that influence the physical appearance of any living thing.
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Kentucky Department of Education
Performance Events 1993-94