Thirteen Ed Online - Genes at Work

		Genes at Work The following chart will help you complete your Web lesson. Print this page and continue with the lesson. The topic of Sifting the Genes of Life and Death in the Web companion piece to the INNOVATION series is how a genetic disease affects two families. Laurie and Claudio's son, Joey, was born with epidermolysis bullosa (EB). This outcome was unexpected: Both parents were healthy but they carried the recessive, defective gene for this disease. It is difficult to predict whether a child whose parents both carry recessive genes for a disease will have that disease. The case of Steve and Fiona underscores this. Their daughter Alison, born with a severe form of EB, was thought to be at low risk because her older sister, Katie, was healthy. Following is a chart that shows the genetic makeup of a family with respect to EB. The gene that causes EB is recessive. For someone to have the disease, they have to have 2 copies of the recessive gene - one from each parent. Use the chart to answer the following questions. The ovals show the recessive and dominant genes: For a dominant gene, fill in the oval; for a recessive gene, leave it blank. What combinations of recessive and dominant genes could children of these parents inherit? Does the sex of the children make any difference? Steve and Fiona's daughter Katie is healthy. Speculate about the combination of recessive and dominant genes for EB she inherited. Make predictions about the health of each child on the chart. Suggest ways that Fiona and Steve might conceive a healthy baby. What, if any, are the moral implications?