Question

the change in the instruction caused the protein to ________. be incomplete. (we couldn’t finish building the protein.) no longer exist. have a different structure. have the same structure.

Explanation:

This question is about protein synthesis and the effect of a change in the "instruction" (likely DNA or RNA instructions for protein building). A change in the genetic code or the process of translation/transcription can lead to a protein with a different structure (due to changes in amino acid sequence) or an incomplete protein (if, for example, a stop codon is prematurely introduced or the process is interrupted). The option "be incomplete. (We couldn’t finish building the protein.)" is a common result of certain mutations (like nonsense mutations) or errors in the process that stop protein synthesis early. The option "no longer exist" is incorrect as the protein would still be present (just incomplete or altered). "Have the same structure" is incorrect because a change in instruction would change the structure. "Have a different structure" is also a possible result (like from missense mutations), but the parenthetical in the first option gives a clear context of not finishing the protein, making "be incomplete" the most fitting here.

Answer:

be incomplete. (We couldn’t finish building the protein.)