Question

Choose the incorrect statement for cDNA libraries.

(a) They constitute of DNA copies produced from the RNA sequences and usually mRNA

(b) They represent expressed sequences

(c) Introns are not represented

(d) Comparison of cDNA sequences with genomic sequences leads to the determination of polyadenylation sites

I have been asked this question during an interview.

The doubt is from cDNA Libraries, Polyadenylated RNA and cDNA Synthesis topic in division Libraries Construction of Genetic Engineering

Answer 1

The correct option is (c) Introns are not represented

The best explanation: cDNA libraries constitute of DNA copies produced from RNA sequences and usually mRNA. They are not only the collection of expressed sequences but post transcriptional changes are also recorded. Introns can also be represented. Comparison of cDNA sequences with genomic sequences can lead to the determination of positions of introns, polyadenylation sites etc.