BIO 151 EXAMS SET VERIFIED QUESTIONS
AND ACCURATE ANSWERS COMPLETE
PREPARATION FILE
●● Why are viruses not considered alive?
Answer: They cannot reproduce on their own, have no cells, and lack
metabolism
●● What is the lytic cycle?
Answer: A viral cycle where the virus replicates immediately and causes
the host cell to burst
●● What is the lysogenic cycle?
Answer: A viral cycle where viral DNA integrates into the host genome
and replicates with the cell
●● What is viral DNA called when it is integrated into the host
chromosome?
Answer: A prophage
●● What is the main difference between enveloped and nonenveloped
viruses?
, Answer: Enveloped viruses have a lipid membrane; nonenveloped
viruses do not.
●● What enzyme do retroviruses use?
Answer: reverse transcriptase
●● What is the defining feature of retroviruses
Answer: They convert RNA → DNA using reverse transcriptase.
●● What is the first step in the HIV infectious cycle?
Answer: Binding to CD4 receptors on host cells.
●● What happens during reverse transcription in HIV?
Answer: Viral RNA is converted into DNA.
●● What happens during integration in HIV?
Answer: Viral DNA is inserted into the host cell's genome.
●● What is the cost to the host cell during viral replication?
Answer: The cell uses its energy and nutrients to make viral
components.
●● What type of genetic material can viruses have?
AND ACCURATE ANSWERS COMPLETE
PREPARATION FILE
●● Why are viruses not considered alive?
Answer: They cannot reproduce on their own, have no cells, and lack
metabolism
●● What is the lytic cycle?
Answer: A viral cycle where the virus replicates immediately and causes
the host cell to burst
●● What is the lysogenic cycle?
Answer: A viral cycle where viral DNA integrates into the host genome
and replicates with the cell
●● What is viral DNA called when it is integrated into the host
chromosome?
Answer: A prophage
●● What is the main difference between enveloped and nonenveloped
viruses?
, Answer: Enveloped viruses have a lipid membrane; nonenveloped
viruses do not.
●● What enzyme do retroviruses use?
Answer: reverse transcriptase
●● What is the defining feature of retroviruses
Answer: They convert RNA → DNA using reverse transcriptase.
●● What is the first step in the HIV infectious cycle?
Answer: Binding to CD4 receptors on host cells.
●● What happens during reverse transcription in HIV?
Answer: Viral RNA is converted into DNA.
●● What happens during integration in HIV?
Answer: Viral DNA is inserted into the host cell's genome.
●● What is the cost to the host cell during viral replication?
Answer: The cell uses its energy and nutrients to make viral
components.
●● What type of genetic material can viruses have?
