The reaction catalyzed by reverse transcriptase is

A) DNA → mRNA.

B) mRNA → cDNA.

C) mRNA → protein.

D) DNA → DNA.

E) tRNA → mRNA.

(B) mRNA → cDNA.

Explanation:

Reverse transcriptase can be defined as an enzyme, which makes cDNA (complementary DNA) by using mRNA as a template. These enzymes are also known as RNA dependent DNA synthase as they make DNA by using information present in RNA.

These enzymes are used by eukaryotes (as telomerase) to replicate chromosome ends or telomeres, by retrotransposon, and by some viruses, such as retroviruses to replicate their genetic material.

Thus, the correct answer is option (B).

mRNA → cDNA

Explanation:

Reverse transcriptase enzyme is generally used by the retrovirus for their genome replication. This enzyme was discovered by Howard tenim.

Reverse transcriptase enzyme generates the complementary DNA from the mRNA template by the process of reverse transcription. The presence of RNase H, RNA-dependent DNA polymerase and DNA-dependent DNA polymerase activity enable the enzyme to convert the mRNA into DNA.

Thus, the correct answer is option (B).