Dropping Genes

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					                                 Dropping Genes

Explanation: You are a member of an alien species called the grokloin. Unlike humans who
have 46 chromosomes, the grokloin have only ten chromosomes (five homologous pairs). You
and your partner will mate, and are going to have a child. As you know, when you mate, the
offspring will inherit half their genes from the dad, and half from the mom.

Instructions for working alone:
   1. Look at your chromosomes and your trait map. Use the information provided to fill
       out the parent (mom or dad) profile.
   2. Write down the name of each gene in the chart under “gene name.” This name can be
       found in the trait map.
   3. Write the alleles you have for each chromosome in the chart provided. The alleles
       will be found on the chromosomes (the slips of paper).
   4. Use your knowledge of allele combinations (dominant and recessive) to record each
       trait that your parent displays under “trait expressed.” For example, if your parent
       has an “A” and an “a” for chromosome #1, then you would write “green skin”.
Instructions for working together:
   1. You will be paired with a mate. Each of you has a complete set of chromosomes. Now
       it is time to make a baby!
   2. To accomplish fertilization, you and your mate will each drop your chromosomes one
       by one onto the table top. After dropping your chromosomes, only one allele of each
       chromosome should be visible. Record the two alleles that are facing up under
       “alleles” on the baby‟s chart. For example, both parents will drop their chromosome
       #1 onto the table. If mom‟s chromosome lands with the “a” facing up, and Dad‟s lands
       with “A” facing up, then write “a” and “A” under “alleles” on the baby chart and move
       to chromosome #2.
   3. Finish filling in the baby‟s chart by writing the gene name for each set of
       chromosomes, and use the rules of dominance to determine the trait expressed for
       each allele pair.
   4. Select a name for your baby, and then create a birth certificate.
   5. Use the markers or pencils to draw a baby photo.
   6. Collect all the chromosomes and repeat steps 2 - 3 for two more offspring.
   7. Draw a family photo showing both parents and three offspring.
   8. Write a paragraph comparing the traits present in the three offspring. Are they
       identical, similar or dissimilar? How can three children of the same parents have
       such different traits?
To turn in:
   1. Completed chart for each parent and child
   2. Birth certificate and baby photo for child
   3. Family photo with both parents and child
   4. Paragraph comparing and contrasting traits in parents & 3 offspring
                                 Trait Map

1.   Chromosome #1: The gene in this chromosome codes for skin color. A dominant
     allele (A) = green skin. A recessive allele (a) = orange skin

2. Chromosome #2: The gene in this chromosome codes for face markings. A dominant
   allele (B) = freckles. A recessive allele (b) = no freckles

3. Chromosome #3: The gene in this chromosome codes for tooth shape. A dominant
   allele (C) = rounded teeth. A recessive allele (c) = pointed teeth

4. Chromosome #4: The gene in this chromosome codes for ear shape. A dominant
   allele (D) = pointed ears. A recessive allele (d) = square ears

5. Chromosome #5: The gene in this chromosome codes for spot color. A dominant
   allele (E) = red spots. A recessive allele (e) = yellow spots

6. Chromosome #6: The gene in this chromosome codes for eye number. A dominant
   allele (F) = one eye in center of head. A recessive allele (f) = Three eyes, two on
   sides and one in center of head

7. Chromosome #7: The gene in this chromosome codes for webbing. A dominant allele
   (G) = webbing between toes and fingers. A recessive allele (g) = no webbing

8. Chromosome #8: The gene in this chromosome codes for nose shape. A dominant
   allele (H) = nose shaped like a squash. A recessive allele (h) = nose shaped like a
   carrot

9. Chromosome #9: The gene in this chromosome codes for arm type. A dominant
   allele (I) = fins. A recessive allele (i) = claws

10. Chromosome #10: The gene in this chromosome codes for gender. An „XX‟ codes for
    female. An „XY‟ codes for male

				
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