EVERYDAY SCIENCE

Detailed explanation-1: -Viruses contain either RNA or DNA as their genetic material. DNA in most organisms is a double-stranded structure, based on Watson and Crick pairing; however, in viruses, DNA and RNA can be either single-stranded or double-stranded.

Detailed explanation-2: -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-3: -Definition. A retrovirus is a virus that uses RNA as its genomic material. Upon infection with a retrovirus, a cell converts the retroviral RNA into DNA, which in turn is inserted into the DNA of the host cell. The cell then produces more retroviruses, which infect other cells.

Detailed explanation-4: -The Basics of Viruses Unlike all other biological entities, some viruses, like poliovirus, have RNA genomes and some, like herpesvirus, have DNA genomes. Further, some viruses (like influenza virus) have single-stranded genomes, while others (like smallpox) have double-stranded genomes.

Detailed explanation-5: -DNA viruses all replicate in the nucleus except for the pox virus, which replicates in the cytoplasm. RNA viruses all replicate in the cytoplasm except for the inflenza virus and retroviruses, which replicate in the nucleus.