Cyclostomata are fish

a. made of cartilage
b. without a jaw
c. made of bone

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.

What are characteristics of minerals? select 3 choices

When the oxygen produced by photosynthetic plants in the water dissolves in the water, which of these is being formed?