BIO 253 CHAP 6 & 7 Exam | Atcual Questions
and Answers with Verified Solutions | Latest
Updated 2026
Viruses Infectious, acellular pathogens; obligate
intracellular parasites.
Living Status of Viruses Not considered living organisms.
Genome type DNA or RNA genome (never both).
Structure of viruses Nucleic acid surrounded by a protein
capsid; some
have a phospholipid membrane.
Capsid Protein coat.
Capsomeres Protein subunits of the capsid.
Enveloped viruses Capsid surrounded by a lipid layer
obtained from
host cell.
Naked viruses (non-enveloped) Formed from only nucleic acid and capsid.
, Spikes Protein structures that allow the virus to
attach and
enter a cell.
Host range Typically infect specific hosts and specific
cell
types.
Virions New virus particles assembled in host cell
to
transport viral genome to another host cell.
Vector Animal that transmits a pathogen from one
host to
another.
Mechanical transmission Arthropod carries pathogen on outside of
body.
Biological transmission Arthropod carries pathogen inside body
and
transmits through biting.
Zoonoses Viruses transmitted from animal host to
human
host.
Viral replication requirement Require exploitation of host-cell genomes
to
reproduce.
and Answers with Verified Solutions | Latest
Updated 2026
Viruses Infectious, acellular pathogens; obligate
intracellular parasites.
Living Status of Viruses Not considered living organisms.
Genome type DNA or RNA genome (never both).
Structure of viruses Nucleic acid surrounded by a protein
capsid; some
have a phospholipid membrane.
Capsid Protein coat.
Capsomeres Protein subunits of the capsid.
Enveloped viruses Capsid surrounded by a lipid layer
obtained from
host cell.
Naked viruses (non-enveloped) Formed from only nucleic acid and capsid.
, Spikes Protein structures that allow the virus to
attach and
enter a cell.
Host range Typically infect specific hosts and specific
cell
types.
Virions New virus particles assembled in host cell
to
transport viral genome to another host cell.
Vector Animal that transmits a pathogen from one
host to
another.
Mechanical transmission Arthropod carries pathogen on outside of
body.
Biological transmission Arthropod carries pathogen inside body
and
transmits through biting.
Zoonoses Viruses transmitted from animal host to
human
host.
Viral replication requirement Require exploitation of host-cell genomes
to
reproduce.
