1. Which of the following is not a type of viral reproduction?
A. DNA virus in a lytic cycle
B. DNA virus in a lysogenic cycle
C. DNA virus (single-stranded) with a double-stranded DNA intermediate
D. RNA virus with reverse transcription to make cDNA
E. RNA virus acting as tRNA

2. In the lysogenic cycle of bacteriophage ?,
A. a repressor, cI, blocks the lytic cycle.
B. the bacteriophage carries DNA between bacterial cells.
C. both early and late phage genes are transcribed.
D. the viral genome is made into RNA, which stays in the host cell.
E. many new viruses are made immediately, regardless of host health.

3. An operon is
A. a molecule that can turn genes on and off.
B. an inducer bound to a repressor.
C. a series of regulatory sequences controlling transcription of protein-coding genes.
D. any long sequence of DNA.
E. a promoter, an operator, and a group of linked structural genes.

4. In DNA, 5-methylcytosine
A. forms a base pair with adenine.
B. is not recognized by DNA polymerase.
C. is related to transcriptional silencing of genes.
D. does not occur at promoters.
E. is an irreversible modification of cytosine.