Which of the following statements about erosion is true?
a.
erosion occurs as a result of drastic changes in temperature.
b.
erosion occurs when wind or water moves over sediment, soil, or rocks.
c.
physical and chemical are the two types of erosion.
d.
movement is not required for erosion to take place.

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?