Question

A consensus sequence is a series of bases or types of bases commonly found at a specific position in the genomes of multiple individuals. The two types of bases are purines (R) and pyrimidines (Y). The following table shows the nucleotide sequence of a region of gene X from six different individuals. Nucleotide positions are labeled 1 through 7.

A A T A G T A

A A T T A T A

A C C T G T T

A A C T A T T

A A A A G T A

A C A T A T A

Compare the sequences of all six individuals to determine the consensus sequence for this region of gene X.

1- ACYARTT             2- AAYTATA                 3- AATTGTA                    4- AARTYTA                    5- AAYTRTA

Answer 1

All the sequence has A at position 1 and T at position 6.

So they will present in the consensus sequence.

At position 3 there is the only pyrimidine. So at third position Y will present.

At position 5 there is the only purine. So at fifth position R will present.

At second position there are more A than C. So we can take A in the second position.

At fourth position, there are more T than A. So we can take T in the second position.

At seventh position there are more A than T. So we can take A in the second position.

So the consensus sequence could be - AAYTRTA.

So correct answer is option 5- AAYTRTA