This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Molecular Genetics, Subject name: Biochemistry
Which of the following enzymes is used in Recombinant DNA research for Homopolymer tailing? 
Select and explain. 
A. Reverse transcriptase, B. S1 Transferase, C. Polynucleotide kinase, D. Terminal transferase.
D: Terminal transferase.
Answer: D: Terminal transferase. 
Explanation: Ans. D. Terminal transferaseSome of the Enzymes Used in Recombinant DNA ResearchEnzymeReactionPrimary UseAlkaline phosphataseDephosphorylates 5' ends of RNA and DNARemoval of 5'-PO4 groups prior to kinase labeling; also used to prevent self-ligationBAL 31 nucleaseDegrades both the 3' and 5' ends of DNAProgressive shortening of DNA moleculesDNA ligaseCatalyses bonds between DNA moleculesJoining of DNA moleculesDNA polymerase ISynthesizes double-stranded DNA from single- stranded DNASynthesis of double-stranded cDNA; nick translation; generation of blunt ends from sticky endsDNase IUnder appropriate conditions, produces single- stranded nicks in DNANick translation; mapping of hypersensitive sites; mapping protein-DNA interactionsExonuclease IIIRemoves nucleotides from 3' ends of DNADNA sequencing; mapping of DNA-protein interactionsExonucleaseRemoves nucleotides from 5' ends of DNADNA sequencingPolynucleotide kinaseTransfers terminal phosphate (position) from ATP to 5'-OH groups of DNA or RNA32P end-labeling of DNA or RNAReverse transcriptaseSynthesizes DNA from RNA templateSynthesis of cDNA from mRNA; RNA (5' end) mapping studiesS1 nucleaseDegrades single-stranded DNARemoval of "hairpin" in synthesis of cDNA; RNA mapping studies (both 5' and 3' ends)Terminal transferaseAdds nucleotides to the 3' ends of DNAHomopolymer tailing