What are the characteristics of a scientific theory

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?

Select the word from the list that best fits the definition apparent movement of a star used to measure its distance from earth

Based on their relative positions in the periodic table, which two elements would have the same number of valence electrons?