A. Natural selection results in those individuals within a population who are best-adapted surviving and producing more offspring. The traits that promote survival are heritable.
Explanation:
Natural selection works on the genetic variations that are already present in the natural populations. Some organisms of a population are more likely to produce more offspring than the others. This is due to the presence of beneficial genetic traits in these individuals that impart survival and reproductive fitness to them. Natural selection favors those individuals. Over the generations, the frequency of the beneficial genetic trait in the population increases.
Different enzymes have specific active sites which can only catalyze one <span>substrate. Enzyme-substrate complexes are produced only when the substrate fits into the active site :)</span>