Assuming you do not know the location of the start codon how

Assuming you do not know the location of the start codon, how many possible reading frames are there in a mRNA?

0

3

1

6

4

Solution

The answer is 3.

An open reading frame is a continuous stretch of codons that do not contain a stop codon (usually UAA, UAG or UGA).Since mRNA is interpreted in groups of three nucleotides (codons), a mRNA strand has three distinct reading frames.