The toxicity of marine pollutants is evaluated through bioassays by a) calculating the concentration at which 50% of the test organisms of a particular species die b) determining the length of time the pollutant remains in the environment c) estimating the number of trophic transfers in the food web affected by the pollutant d) determining the total biomass of affected organisms in the environment

Why might a single rock layer exhibit different types of sedimentary rocks within it? view available hint(s) why might a single rock layer exhibit different types of sedimentary rocks within it? such a rock layer, termed a facies, when traced laterally represents a variety of depositional environments that formed in a sequence over time. such a rock layer, termed a facies, when traced laterally represents a single depositional environment that formed over time. such a rock layer, termed a facies, when traced vertically represents a variety of depositional environments that formed at the same time across a broad area. such a rock layer, termed a facies, when traced laterally represents a variety of depositional environments that formed at the same time across a broad area. such a rock layer, termed a facies, when traced vertically represents a variety of depositional environments that formed in a sequence over time.