Which statement is scientifically based? Mutations rarely occur. All mutations are harmful. Some mutations can be contagious, like infections. Mutations are not passed from parent to offspring.

Mutations rarely occur

Explanation:

Mutations are genetic changes, i.e., alterations in the DNA sequence. Generally, mutations have deleterious effects, but there are exceptions where mutations may confer an adaptive advantage in a given environment. Mutations are often deleterious, and thereby these genetic changes are rare events. In consequence, mutation rates, i.e., the frequency by which new mutations arise in an organism over time, are generally very low. Finally, mutations that arise only in germ cells can be inherited from a generation to the next generation, while somatic mutations cannot be inherited.

stratosphere: as the altitude increases, the air temperature increases. the stratosphere has a layer of ozone, called the ozone layer. this layer absorbs most of the ultraviolet radiation from sunlight. this results in the stratosphere being warmer.