What 2 chemicals dose photosynthesis need as reactants

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.

Plz ! having a smooth seeds is the dominant trait. having wrinkled seeds is a recessive trait. the offspring of two plants with smooth seeds, a. must have smooth seeds. b. may have smooth or wrinkled seeds. c. must have wrinkled seeds. d. have a 25% change of having smooth seeds.

Why are fossils not found in igneous rocks? igneous rocks are made from cooling of lava or magma. igneous rocks are found too deep underground. igneous rocks are too dark in color to contain fossils. igneous rocks are too dense to contain fossils.