EVERYDAY SCIENCE

Detailed explanation-1: -Viruses are smaller and simpler in construction than unicellular microorganisms, and they contain only one type of nucleic acid-either DNA or RNA-never both.

Detailed explanation-2: -A virus is made up of a core of genetic material, either DNA or RNA, surrounded by a protective coat called a capsid which is made up of protein. Sometimes the capsid is surrounded by an additional spikey coat called the envelope. Viruses are capable of latching onto host cells and getting inside them.

Detailed explanation-3: -While most viruses contain a single segment of nucleic acid, others have genomes that consist of several segments. DNA viruses have a DNA core. The viral DNA directs the host cell’s replication proteins to synthesize new copies of the viral genome and to transcribe and translate that genome into viral proteins.

Detailed explanation-4: -A virus is an infectious particle that reproduces by “commandeering” a host cell and using its machinery to make more viruses. A virus is made up of a DNA or RNA genome inside a protein shell called a capsid.

Detailed explanation-5: -The larger viruses contain in a core the nucleic acid genome complexed with basic protein(s) and protected by a single-or double layered capsid (consisting of more than one species of protein) or by an envelope (Fig. 41-5).