What was one of the ways thy people of ancient times classified plants and animals

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Dna and rna share a number of similarities,but they also differ in certain aspects of their structure. wich nitrogenous base is found in rna but is not found in dna

During convection, less dense fluid rises and denser fluid sinks.