Tropical and polar climate zones are very distinct. this is because
a. the sun's rays are more concentrated near the equator
b. the sun's rays are more concentrated near the poles
c. the poles absorb sunlight more effectively
d. clouds reflect more sunlight at the equator

identify the dna change shown in the diagram and explain how that change can result in the increased genetic diversity often seen among siblings.identify the dna change shown in the diagram and explain how that change can result in the increased genetic diversity often seen among siblings.v

scientists have discovered that hiv does not cause aids by the virus's direct effect on the host's immune cells, but rather through the cells' lethal influence on one another. researchers from the gladstone institutes have revealed that hiv does not cause aids by the virus's