Write a scientific argument that addresses the question: Why is Jackie an elite distance runner when no one else in her family has that trait?
1. Review your completed Reasoning Tool. Be sure to include your strongest piece of evidence and make a
connection between the pieces of evidence that go together.
2. State your claim, explaining how it leads to Jackie's trait for running ability. Then, use the evidence to support
your claim.
3. Use the Scientific Argument Sentence Starters above to help you explain your thinking.
4. To make your argument more convincing, be sure to answer the following questions:
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Which combinations of gene versions do you think Jackie's mom has? Explain your thinking.
Which combinations of gene versions do you think Jackie has? Explain your thinking.
How do Jackie's gene versions relate to her trait for running ability?

A mutation in Jackie's genes culminated in developing a new enzyme, resulting in the long-distance running phenotype. Jackie appears to have either the A1Am or A2Am gene variants. Jackie used to play for long periods without tiring, suggesting that her gene variants could generate a protein that results in a stamina feature. Jackie's father bears the A1A2 gene. Since Jackie's mother is a good sprinter, I suspect she bears A1A1 gene variants. Sprinters have much ACTN3 protein in their cells, so that she may have two copies of the A1 gene variant. This means Jackie has at least one clone of the A1 gene allele. People with one or two versions of the A1 gene variant, on the other hand, are rarely successful long-distance runners. Out of 100 total distance runners, only 28 (25 and 3) have an A1 gene copy. Since the gene variants she may have inherited from her parents cannot justify her stamina, she may have a mutant gene version that contains a long-distance running protein. However, I do not believe she has AmAm gene versions because mutations are uncommon. Jackie is an elite long-distance runner due to a gene that no one else in her family has.