🧬 Viruses in the Environment — Comprehensive Notes

A virus is an ____________ intracellular parasite.

obligate

All viruses contain nucleic acid and a ____________.

capsid

Some viruses also have an ____________, which is a lipid bilayer derived from the host membrane.

envelope

In the Baltimore classification system, viruses are classified based on genome type, strand type, and ____________ production strategy.

mRNA

Viruses are found in oceans at a concentration of ____________ viruses/mL.

10⁶–10⁸

Viruses can infect all domains of life, including bacteria, archaea, plants, animals, and ____________.

fungi

Viruses play a crucial role in controlling microbial populations and driving ____________ cycling.

nutrient

Plant viruses require ____________ plant cells to replicate and cannot enter via endocytosis or membrane fusion.

living

Tobacco mosaic virus (TMV) is a ____________ virus with a +ssRNA genome.

non-enveloped

The life cycle of TMV includes entry, uncoating, early gene expression, genome replication, assembly, cell-to-cell movement, and ____________ spread.

systemic

Herpes simplex virus (HSV) is classified as a ____________ virus with a dsDNA genome.

Baltimore Class I

During the life cycle of HSV, the virus enters the host cell through ____________ fusion.

membrane

The CTXφ bacteriophage infects ____________ cholerae and can produce cholera toxin genes.

Vibrio

In the lytic cycle, the bacteriophage causes host cell ____________ and releases new phages.

lysis

CTXφ converts otherwise harmless bacteria into ____________ by encoding toxin-producing genes.

pathogens