Polydactyly

• What physical characteristic is associated with polydactyly?

  Extra fingers or toes
• What type of allele causes polydactyly?

  A dominant allele
• What does it mean if someone has one copy of the polydactyly allele and one copy of the normal allele?

  They will have polydactyly
• Can you be a carrier of the polydactyly allele?

  No, you cannot
• What is true of any dominant allele?

  If you have it, you have the characteristic
• What genotypes describe a heterozygous individual?

  Different alleles for a trait
• If 50% of offspring are heterozygous for the polydactyly allele, what condition do they have?

  They will have polydactyly
• If 50% of the offspring are unaffected by polydactyly, what does this mean?

  They do not have the polydactyly allele
• In the cross described, what is the ratio of polydactyly to unaffected offspring?

  1 to 1
• What do the percentages and ratios calculated in a Punnett square represent?

  Probabilities
• What is a potential outcome of a genetic cross?

  All offspring could have polydactyly
• Besides cystic fibrosis, what is another inherited disorder mentioned?

  Polydactyly
• What is one potential solution to inherited disorders?

  Embryo screening
• What happens to embryos identified as not having defective alleles during embryo screening?

  They are implanted into the woman
• What is the goal of implanting embryos without defective alleles?

  To develop into healthy offspring
• What is something you might be asked to do in an exam regarding embryo screening?

  Discuss the issues around embryo screening
• What is the first potential problem with embryo screening?

  It is expensive
• What do some people think about the money spent on embryo screening?

  It should be spent elsewhere
• What happens to a large number of embryos during screening?

  They are created, but only some implanted
• Why do some people find the destruction of healthy embryos unethical?

  Because they are healthy
• What might embryo screening be used for in the future?

  To produce offspring with desirable features
• What do many people find unethical about screening for desirable traits?

  The potential for designer babies
• What is the name of the future potential therapy that may correct faulty alleles?

  Gene therapy
• Where can you find additional questions on polydactyly and embryo screening?

  In the revision workbook
• What is the current status of gene therapy?

  It is still experimental