"which maternal condition is considered a contraindication"

When fossil fuels are burned, carbon dioxide is released. how does this gas impact the environment?

On his trip to the galapagos islands, darwin determined that animals on the islands

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?