How do biozones scientists determine the age of a rock unit? a specific biozone can indicate a particular type of past environment. a biozone can trace the path of evolution over time. the relative age of the rock can be determined by the types of fossils it contains. the fossils in different rock layers are not related to each other?

The correct answer is that a biozone can help in tracing the path of evolution over time.  

Biozone refers to a stratigraphic unit that comprises fossils in the layers of strata prevailed in a specific geologic period. It is termed as biozone as it signifies the number of biological taxa prevailed in specific strata. Thus, the changes in characteristics within the taxonomic groups in biozones can provide the indication of evolution with regard to time.  

If one side of the Earth faces the sun, it will be warmer thus being spring or summer. On the other side of Earth that is not facing the sun, it will be colder because the sun is facing the other direction, and the side without sunlight will result in colder weather, as the season being winter or fall.