You isolate a bacteriophage that can replicate in E. coli. Through chemical analyses you determine that the only nucleic acid present is RNA. You isolate the RNA and put it in a test tube with all of the enzymes, amino acids, and RNAs necessary for translation. The RNA is translated directly, without being copied into a complementary strand first, and new infectious virions are made and released. What does this tell you about the bacteriophage?
A) The viral genome is ssRNA of the plus sense.
B) The viral genome is ssRNA of the minus sense.
C) The bacteriophage is a retrovirus.
D) The bacteriophage is probably a new strain and should be studied further.

Question

Quizplus · Accepted Answer

The fact that the RNA is translated directly and that new infectious virions are made and released indicates that the viral genome is of the plus sense, meaning it can be directly translated into protein without the need for a complementary strand. Retroviruses, on the other hand, have a RNA genome that must be reverse transcribed into DNA before being integrated into the host genome. Therefore, choice A is the most likely option. Choice B and C can be ruled out based on the given information. D may be a possibility, but there is enough information available to make an educated guess about the nature of the bacteriophage.

You Isolate a Bacteriophage That Can Replicate in E