Question

3. In most cells,

Answer 1

Answer:

In most cells, DNA directs the production of a molecule of mRNA which then enters a ribosome. The ribosome produces the final product, a protein. Retroviruses do the opposite. They use the enzyme reverse transcriptase to use a template of mRNA to produce DNA.

Explanation:

The central dogma of molecular biology describes how a cell uses its genetic information to synthesize a protein. The first step called 'transcription' consists of using an RNA polymerase enzyme and a fragment of DNA (i.e., gene) as a template to synthesize an RNA molecule, usually a messenger RNA (mRNA). Subsequently, the genetic code in the mRNA sequence is read by the ribosomes in order to produce a protein, a process known as 'translation'. Retroviruses are viruses that have the ability to integrate into the host genome by using a reverse transcriptase enzyme that allows reverse transcription of mRNA to complementary DNA, which then integrates into the host's genome.