HELP! What’s the trophic level of a black dragonfish?

How is ribosomal rna useful as a molecular clock? a. a large portion of the dna ring is not vital to structure or function, allowing it to accumulate neutral mutations. b. its rate of mutation increases over time as organisms continue to evolve and differentiate from each other. c. a slow mutation rate makes it useful for determining evolutionary relationships between ancient species. d. it is only found in select organisms, making it easier to compare relationships between species that have it.

If the temperature in an area drops five degrees between one day and the next, has the climate of the area changed? explain.

After agricultural soils are picked up and carried by a river, how are they deposited in the river’s del which is not a cause of desertification? a) light grazing b) contour plowing c) conversion of rangelands to crop lands d) high population density