Which element is capable of forming long chains by forming single, double, or triple bonds with itself? a) carbon b) hydrogen c) nitrogen d) oxygen

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.

Which worm has eyespots that are used to detect light? a fluke b marine worm c planarian d tapeworm

What type of plant is good for a bioassay and where can i buy it? i only have a month.