Unit 3 Exam - Bio 180 questions and answers 2026\2027
A+ Grade
virus
- correct answer An infectious particle consisting of more than genes packed into a protein
capsid
- correct answer Outer protein coat of a virus
viral envelope
- correct answer A membrane that cloaks the capsid that in turn encloses a viral genome.
phages
- correct answer A virus that infects bacteria; also called a bacteriophage.
capsomere
- correct answer protein subunits that make capsids
glycoproteins
- correct answer A protein with one or more covalently attached carbohydrates.
obligate parasite
- correct answer a parasite that cannot live apart from its host
host range
- correct answer limited range of host cells that each virus can infect
lytic cycle
- correct answer A type of viral replication cycle resulting in the release of new viruses by lysis (breaking
open) of the host cell.
, lysogenic cycle
- correct answer a viral reproductive cycle in which the viral DNA is added to the host cell's DNA and is
copied along with the host cell's DNA
restriction enzymes
- correct answer Enzyme that cuts DNA at a specific sequence of nucleotides
T4 phages
- correct answer Lytic phage
prophage
- correct answer A phage genome that has been inserted into a specific site on the bacterial
chromosome.
retrovirus
- correct answer An RNA virus that reproduces by transcribing its RNA into DNA and then inserting the
DNA into a cellular chromosome; an important class of cancer-causing viruses.
reverse transcriptase
- correct answer An enzyme encoded by certain viruses (retroviruses) that uses RNA as a template for
DNA synthesis.
vaccine
- correct answer A harmless variant or derivative of a pathogen that stimulates a host's immune system
to mount defenses against the pathogen
epidemic
- correct answer A widespread outbreak of an infectious disease.
pandemic
- correct answer A worldwide epidemic.
A+ Grade
virus
- correct answer An infectious particle consisting of more than genes packed into a protein
capsid
- correct answer Outer protein coat of a virus
viral envelope
- correct answer A membrane that cloaks the capsid that in turn encloses a viral genome.
phages
- correct answer A virus that infects bacteria; also called a bacteriophage.
capsomere
- correct answer protein subunits that make capsids
glycoproteins
- correct answer A protein with one or more covalently attached carbohydrates.
obligate parasite
- correct answer a parasite that cannot live apart from its host
host range
- correct answer limited range of host cells that each virus can infect
lytic cycle
- correct answer A type of viral replication cycle resulting in the release of new viruses by lysis (breaking
open) of the host cell.
, lysogenic cycle
- correct answer a viral reproductive cycle in which the viral DNA is added to the host cell's DNA and is
copied along with the host cell's DNA
restriction enzymes
- correct answer Enzyme that cuts DNA at a specific sequence of nucleotides
T4 phages
- correct answer Lytic phage
prophage
- correct answer A phage genome that has been inserted into a specific site on the bacterial
chromosome.
retrovirus
- correct answer An RNA virus that reproduces by transcribing its RNA into DNA and then inserting the
DNA into a cellular chromosome; an important class of cancer-causing viruses.
reverse transcriptase
- correct answer An enzyme encoded by certain viruses (retroviruses) that uses RNA as a template for
DNA synthesis.
vaccine
- correct answer A harmless variant or derivative of a pathogen that stimulates a host's immune system
to mount defenses against the pathogen
epidemic
- correct answer A widespread outbreak of an infectious disease.
pandemic
- correct answer A worldwide epidemic.
