Which of the following is not part of a good scientific theory?
a. a scientific theory must explain a wide variety of phenomena observed in the natural world.
b. a scientific theory cannot be accepted until it has been proven true beyond all doubt.
c. a scientific theory must make testable predictions that, if found to be incorrect, could lead to its own modification or demise.
d. a scientific theory should be based on natural processes and should not invoke the supernatural or divine.

The empty trna moves off and picks up another matching amino acid from the cytoplasm in the cell. the anticodon of the trna, with its attached amino acid, pairs to the codon of the mrna, which is attached to a ribosome. this sequence is repeated until the ribosome reaches a stop codon on the mrna, which signals the end of protein synthesis. the ribosome forms a peptide bond between the amino acids, and an amino acid chain begins to form. when a second trna with its specific amino acid pairs to the next codon in sequence, the attached amino acid breaks from the first trna and is bonded to the amino acid of the second trna.