<span>The correct answer is chemical covalent energy. This energy is stored and when the bonds break the energy is released. You also need energy to break them. The most common form is a single bond but there are examples where there are double and triple bonds when building various compounds.</span>
Answer:
Because natural selection selects for it. Thus it persists.
Explanation:
You have to understand heterozygote advantage. Basically, it's where heterozygotes have an advantage over homozygotes. In the case of sickle cell disease, heterozygotes have an advantage, and natural selection favors whatever is advantageous. Thus, because heterozygotes each have one recessive sickle-cell allele, as natural selection favors the heterozygotes, the recessive sickle-cell allele persists and remains in the gene pool.
The answer is 2 because its the outside number and not in the parentheses
No because a chemical reaction that is at equilibrium in living cells is not capable of doing any work