Answer:
C. 3´OH
Explanation:
DNA is a large molecule built up by linking together smaller molecules called nucleotides.
A nucleotide contains a phosphate group, a sugar (deoxyribose in the case of DNA) and a nitrogen base.
The <em>nucleotides are linked together by the binding of</em> the phosphate group on carbon 5 in the nucleotide that is added, and the oxygen of the hydroxyl group (-OH) on carbon 3 of the last nucleotide of the DNA chain.
These bonds are called phosphodiester bonds and their formation releases a molecule of H2O.
This reaction is catalyzed by an enzyme, DNA polymerase, that requires a free 3´ hydroxyl group (3´ OH in the growing chain) to add the new nucleotide.
I think the correct answer from the choices listed above is option A. The symbiotic relationship describes the association of hermit crabs and snails is commensalism. It is a relationship between organisms where one receives a benefit or benefits from the other and the other is not affected by it.
Answer;
-All of the above
-Storms, factories, and farms
Explanation;
-There are many causes for water pollution but two general categories exist: direct and indirect contaminant sources.
-Direct sources include effluent outfalls from factories, refineries, waste treatment plants etc.. that emit fluids of varying quality directly into urban water supplies.
-Indirect sources include contaminants that enter the water supply from soils/groundwater systems and from the atmosphere via rain water. Soils and ground waters contain the residue of human agricultural practices (fertilizers, pesticides, etc..) and improperly disposed of industrial wastes.
<u>Answer</u>: D. The inside of the cell becomes less negative in charge relative to the outside of the cell.
During depolarization, the membrane potential moves towards zero. This process is initiated by 
that enters the cell due to the polarization of the cell. Outside of the cell, the concentration of the positively charged sodium ion is higher by a factor of 10, compared with the interior of the cell. Due to the presence of the sodium cation in increasing amounts inside the cell, the relative voltage will change immediately. This will result in an interior of the cell that is less negative in charge relative to the outside of the cell.
