How do biozones scientists? choose all that apply. a) the relative age of the rock can be determined by the types of fossils it contains. b) rock layers in different locations that contain the same fossils may be considered the same age. c) a biozone can trace the path of evolution over time. d) a specific biozone can indicate a particular type of past environment.

 C). A biozone can help trace the path of evolution over time.

Biozone is a stratigraphic unit which contains fossils in layers of strata existed in a particular geologic period.  It is named as biozone because it depicts the number of biological taxa existed in particular strata. Therefore, the variation in features within taxonomic groups in biozones can give indication of evolution with respect to time.  

option a is correct i.e.

explanation:

in context to the membrane of nerve impulse, the outer membrane of neuron is semi permeable that is only sodium ions can pass through the membrane i.e. smaller ions can pass through the membrane while larger ions cannot pass through it.