These preparations are called Vaccines. A vaccine is a biological preparation that provides active acquired immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing micro-organism and is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins.
Answer: Proteins
Explanation:
Proteins are one of the most plentiful naturally-grown molecules in living systems and possess the most distinctive extent of duties of all macromolecules. The purposes of proteins are highly distinct for 20, unlike chemically different amino acids that develop large chains, plus the amino acids can occur in any method. Proteins may be architectural, regulatory, contractile, or shielding; they may work in transportation, storage, or membranes; or they may be poisons or enzymes. An instance of the function of proteins: proteins can work as enzymes or hormones. Enzymes made by living cells are catalysts in biochemical reactions and are usually proteins.
The answer is letter b. adaptation. Adaptation occurs when living organisms adapt to their surroundings or environment over a long period of time. In this case, Dark Furred Squirrels were abundant, since squirrels adapted to the dark shady area they have lived and adapted into a dark furred one, which allowed it to be more common due to adaptation.