Q19 - Point Mutations, Frameshifts, and Codon Degeneracy
The amino acid sequence MYTHELL is essential for the activity of a given enzyme. Analysis of this enzyme in three related species (A–C, see statements) reveals some diversity. The table below shows the codon usage for the different amino acids in the three organisms
Using the information and data, determine which of the statements are true or which are false.
A. In species A, the enzyme-encoding sequence has changed to MTTHYLL, which can be explained by two point mutations
B. In species B, the sequence is MYYS, which is best explained by a frame shift mutation
C. In species C, the sequence is in fact MYTHELL, but this can be due to 512 different nucleotide sequences
D. On average, a change from MYTHELL to MYTQELL is more likely than a change to MYTHEHL
Question reproduced from IBO 2015, Theoretical Exam B, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)