One mechanism by which viruses may cause cancer is to interrupt the genetic regulatory sequences of repressor proteins. Which of the following types of viruses is most likely to be involved in causing cancer by this mechanism? A) + ssRNA virusesB) dsRNA virusesC) - ssRNA virusesD) retrovirusesE) + ssRNA and - ssRNA viruses

Answer: D) retroviruses

Explanation:

Retroviruses are a type of virus that converts its genetic material into DNA using a special enzyme, called reverse transcriptase. The DNA is then able to integrate into the DNA of the host cell. Once integrated, the virus can make additional viral particles using the components of the host cell.

Retroviruses which cause cancer at low incidence do not contain host information inserted. Rather, they tend to cause cancer via the expression mutation of potentially oncogenic host genes. Retroviruses incorporate proviral DNA into their host's chromosomal DNA during their natural life-cycle. Provirus DNA promoter affect regulatory gene expression over.

Hence, the correct option is D.