THE MOLECULAR BASIS OF INHERITANCE
RECOMBINANT DNA
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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cDNA does not contain non-coding introns
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size of cDNA is smaller
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cDNA does not have the complete information on the genome of an organism
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fewer types of clones are composed in cDNA library
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Detailed explanation-1: -A cDNA library has the drawback that it only includes sequences that are present in mature mRNA. There are no introns and any other sequences that are modified during transcription; sequences that are not transcribed into RNA, such as promoters and enhancers, are also not present in a library of cDNA.
Detailed explanation-2: -Advantages of cDNA over Genomic DNA No introns: Eukaryote genes commonly contain introns (non-coding sequences). These are removed after mRNA synthesis so cDNA contains no introns. This means that a cDNA copy of a gene can be isolated as a single, intron-free fragment.
Detailed explanation-3: -The genomic DNA libraries comprise large DNA fragments. On the other hand, cDNA libraries are constituted by cloned, reverse-transcribed mRNA. As a result, they are devoid of the DNA sequences relative to the genomic areas which are not expressed such as the introns.