Gene therapy involves:a. replacing all mutant alleles in body cells. b. replacing poor copies of ...

Gene therapy involves:a.
   replacing all mutant alleles in body cells.
  b. replacing poor copies of alleles with normal alleles.
  c. replacing a mutant allele in certain body cells with a normal allele.
  d. repairing mutant alleles in certain body cells.
  e. improving gene expression in key body cells.

Question 2

Why are most infants with phenylketonuria usually healthy at birth?
  a. The defect causing the condition has usually been repaired by that time.
  b. The mother breaks down phenylalanine for both herself and her fetus.
  c. The infant can produce sufficient quantities of the enzymes needed by birth.
  d. Phenylalanine can be completely excreted in infants.
  e. Phenylalanine is completely metabolized in infants