A genetic engineer wants to isolate a gene from a scorpion that encodes the deadly toxin found in its stinger, with the ultimate purpose of transferring this gene to bacteria and producing the toxin for use as a commercial pesticide. Isolating the gene requires a DNA library. Should the genetic engineer create a genomic library or a cDNA library

The correct answer is - Yes, the genetic engineer should create a genomic library or a cDNA library.

Explanation:

mRNA isolated from the toxin extracted from the venom gland of the scorpion to create a cDNA library. The cDNA sequence is reverse transcribed by the mRNA that lacks the introns as prokaryotic organisms such as bacteria cannot splice introns.

If the engineer wants to express the toxin in bacteria then he required a cDNA sequence as a genomic clone can not use to clone for making proteins.  mRNA should be isolated from the venom gland so it can synthesize cDNA library enriched with toxin protein sequence.