International Committee on Taxonomy of Viruses currently classified single stranded DNA viruses into 10 different taxa.
What are the 2 possible genome types A virus may carry?
Chemical Composition and Mode of Replication: The genome of a virus may consist of DNA or RNA, which may be single stranded (ss) or double stranded (ds), linear or circular. The entire genome may occupy either one nucleic acid molecule (monopartite genome) or several nucleic acid segments (multipartite genome).
How is the viral genome different from other genomes?
Although viruses are generally the smallest genomes, as a collection of biological genomes they exhibit the greatest variation. The major difference is that some of the genomes are DNA whereas others are RNA. In addition, both DNA and RNA genomes can be either double- or single-stranded (ds or ss).
What is the largest virus?
Mimivirus is the largest and most complex virus known.
What is a helical virus?
In the case of a helical virus, the viral nucleic acid coils into a helical shape and the capsid proteins wind around the inside or outside of the nucleic acid, forming a long tube or rod-like structure (Fig. 2.4 ). The nucleic acid and capsid constitute the nucleocapsid.
What is coronavirus RNA or DNA?
Coronaviruses (CoVs) are positive-stranded RNA(+ssRNA) viruses with a crown-like appearance under an electron microscope (coronam is the Latin term for crown) due to the presence of spike glycoproteins on the envelope.
Why do viruses have a small genome?
Small genome size is perfectly suited to virus replication, in which each infected host cell produces many copies of the viral genes from a single template. Such exponential replication places a premium on small genome size: the smaller the genome, the faster it can replicate.
Which virus has DNA as its genome?
The genomes of both class I and class II viruses consist of DNA. Various types of DNA viruses are commonly used in studies on DNA replication, genome structure, mRNA production, and oncogenic cell transformation. Class I viruses contain a single molecule of double-stranded DNA (dsDNA).