EVERYDAY SCIENCE

Detailed explanation-1: -Viral Structure. In the simpler viruses the virion consists of a single molecule of nucleic acid surrounded by a protein coat, the capsid; the capsid and its enclosed nucleic acid together constitute the nucleocapsid. In some of the more complex viruses the capsid surrounds a protein core (Fig.

Detailed explanation-2: -The simplest virions consist of two basic components: nucleic acid (single-or double-stranded RNA or DNA) and a protein coat, the capsid, which functions as a shell to protect the viral genome from nucleases and which during infection attaches the virion to specific receptors exposed on the prospective host cell.

Detailed explanation-3: -Enveloped and non-enveloped viruses Viruses are composed of two main components: the viral genome (which can be RNA or DNA) and the virus-coded protein capsid that surrounds the genome. If the virus particle contains only these two elements, it is called a non-enveloped virus.

Detailed explanation-4: -A virus that has an outer wrapping or envelope. This envelope comes from the infected cell, or host, in a process called “budding off.” During the budding process, newly formed virus particles become “enveloped” or wrapped in an outer coat that is made from a small piece of the cell’s plasma membrane.

Detailed explanation-5: -A virus is made up of a DNA or RNA genome inside a protein shell called a capsid. Some viruses have an external membrane envelope. Viruses are very diverse. They come in different shapes and structures, have different kinds of genomes, and infect different hosts.