Question

Which of the following is untrue about Homology-Based Programs?

(a) They are based on the fact that exon structures and exon sequences of related species are less conserved

(b) This approach assumes that the database sequences are correct

(c) It is a reasonable assumption in light of the fact that many homologous sequences to be compared with are derived from cDNA or expressed sequence tags (ESTs) of the same species

(d) Potential coding frames in a query sequence are translated and used to align with closest protein homologs found in databases

The question was posed to me by my college director while I was bunking the class.

My question is taken from Gene Prediction in Eukaryotes topic in section Gene and Promoter Prediction of Bioinformatics

Answer 1

Correct choice is (a) They are based on the fact that exon structures and exon sequences of related species are less conserved

Explanation: Homology-based programs are based on the fact that exon structures and exon sequences of related species are highly conserved. When potential coding frames in a query sequence are translated and used to align with closest protein homologs found in databases, near perfectly matched regions can be used to reveal the exon boundaries in the query.