Can daca students be physician assistant

In dna, only the_ varies from one nucleotide to another. base phosphate sugar amino acid

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Which of the following is likely not involved in this example of ecological succession? a) the rotting remains of plants add to the fertility of the soil. b)the soil becomes so fertile that eel grass is replaced by other plant species. c) the roots from plants stabilize the sediment, keeping it in place. d) the concentration of salt becomes so high that all plant life is destroyed.