Question

If there are 999 bases in an RNA that codes for a protein with 333 amino acids, and the base at position 901 is deleted such that the length of the RNA becomes 998 bases, how many codons will be altered?

• A. 11
• B. 33
• C. 333
• D. 1

Answer 1

The correct option is B 33

There are a total of 999 bases that code for 333 amino acids. 3 bases = 1 amino acid.
If the base at the 901th position is deleted, this means that all the 98 bases after the 901th amino acid would shift one frame before.
99 bases code for 33 amino acids, therefore, the deletion would lead to the alteration for 33 amino acids due to the change in the codons.