What acts as the template for synthesis of a strand of DNA?

a. a ribosome


b. a single strand of tRNA


c. a single strand of rRNA


d. A single strand of DNA


e. A single strand of mRNA

What acts as the template for synthesis of a strand of DNA?
Okay I think the above answers are wrong and here's why. What is the name of the process that actually synthesizes DNA? Think about it. It's not transcription or translation because those processes make mRNA or proteins, correct? And the question that you are posing asks the template for synthesis of a strand of DNA, not mRNA and not RNA or anything like that.


So, when is the only time DNA is being "made"? During DNA replication right? And what is the template used for DNA replication? It's DNA....a single strand of it. The answer is d. If this answer is still not convincing, please review DNA replication (specifically the semi-conservative model of DNA replication) and I think you'll realize that this answer is correct.


I know that sounds super obvious but don't overthink this question.


By the way, the only way "e" would be the right answer is if you are making a cDNA (or complementary DNA) which is common if you want to build a library of DNA with genes important for an organism's function. HOWEVER, this requires the use of an enzyme reverse transcriptase (it does the reverse of transcription and instead goes from mRNA to DNA) and this enzyme is not frequently found in most organisms. It is found naturally in retroviruses like HIV, however. The question you have here does not sound like it's asking for cDNA.


Sorry about all the edits, it's late.
Reply:ya. the first two ans are wrong. DNA can be synthesized using only DNA or mRNA as template. DNA can never be synthesized from A,B,C.(if u can prove it wrong then u will get a noble prize)





out of D and E. D is universal except in few viruses which use E
Reply:d. A single strand of DNA


Each of the parental DNA strand acts as a template for the synthesis of each daughter DNA. DNA can never be synthesised by using tRNA or mRNA.
Reply:d. a single strand of DNA





Actually, you can synthesise DNA from RNA. Some viruses do this with a special enzyme called reverse transcriptase. In most situations though, DNA is replicated from parent DNA.
Reply:E
Reply:Well, you make DNA from RNA, so A and D are out. tRNA, rRNA, and mRNA are left. Of those, which makes the most sense? transfer RNA, messenger RNA?





b