Mutations and Genomic Structure in Viruses

Genome and Genotype

• The genome is the sum of the genes of an organism.
• Genotype refers to the genetic constitution of an organism.

Phenotype

• Phenotype refers to the observable properties of an organism, produced by the genotype in cooperation with the environment.

Viral Genome Variation

• Viruses show variation in their genomic structure by two principal methods: mutations and recombination.
• Mutation is a heritable change in the genotype.

Mutations

• Mutations occur spontaneously and readily in viral genomes, causing frequent changes in the nucleic acids.
• This results in the production of new viral strains showing properties different from parental or wild-type virus.

Wild-Type Virus and Field Isolates

• Wild-type virus denotes the original virus from which mutants are derived and with which the mutants are compared.
• Fresh virus isolates from the natural host are referred to as field isolates or primary isolates.

This quiz covers the basics of genetic mutations, genotypes, and phenotypes in viruses, including spontaneous mutations and their effects on genomic structure.