What happens to the iron (fe3+) that is released during the breakdown of damaged red blood cells?
a. it attaches to transferrin and is transported to bone marrow for use in hemoglobin synthesis.
b. it is used to synthesize proteins.
c. it is utilized by intestinal bacteria to convert bilirubin into urobilinogen.
d. it is converted into urobilin and excreted in urine. it is transported to the liver where it becomes part of bile.

Transposon can cause mutations in genes at or near the site of transposon insertion. it is possible for these elements to transpose away from their original site, causing a reversion of the mutant phenotype. in some cases, however, even more severe phenotypes appear when these elements excise from this site, due to events at or near the mutant allele. what might be happening to the transposon or the nearby gene to create more severe mutations?