cystic fibrosis

Cards (16)

  • What are alleles?
    Different versions of a gene
  • What is the difference between dominant and recessive alleles?
    Dominant alleles are expressed with one copy
  • What is the symbol for the dominant allele for normal cell membrane function?
    Capital C
  • What is the symbol for the recessive allele for defective cell membranes?
    Lowercase c
  • How many copies of the defective allele must a person inherit to have cystic fibrosis?
    Two copies
  • What do we call a person with one defective allele and one normal allele?
    Carrier of the cystic fibrosis allele
  • What is the genotype of a man who is a carrier of the cystic fibrosis allele?
    Heterozygous (C/c)
  • What is the genotype of a woman who is homozygous for the normal allele?
    Homozygous (C/C)
  • What is the first step in constructing a Punnett square?
    Write down the genotypes of the gametes
  • What percentage of offspring will be carriers when a heterozygous man and a homozygous normal woman have children?
    50%
  • What is the genotype of the offspring that do not have cystic fibrosis but are carriers?
    Capital C lowercase c
  • What is the ratio of carriers to non-carriers in the offspring from the cross of a heterozygous man and a homozygous normal woman?
    1:1
  • What is the probability that all offspring could be carriers or all could be unaffected?
    These are just probabilities
  • What is the expected outcome ratio when two carriers of the cystic fibrosis allele have children?
    1:2:1 ratio
  • What percentage of offspring from two carriers will have cystic fibrosis?
    25%
  • What is the ratio of offspring that are homozygous for the normal allele when two carriers have children?
    1 out of 4