Answer:
Organism D.
Explanation:
Amino acids are the monomers of proteins and are linked together by the peptide bond. The protein is obtained from the RNA molecules by the process known as translation.
The amino acid sequence of the proteins can also be used to study the evolutionary relationship between the organisms and the closeness of teh organisms with each other. In the question it is give that organisms A and D has least difference ( 1 amino acid sequence difference) and more related with each other.
Thus, the answer is organism D.
The effects could be, the top consumers may run out of food, which would make it harder for them to catch food
