AP BIOLOGY

Detailed explanation-1: -Still, viruses have some important features in common with cell-based life. For instance, they have nucleic acid genomes based on the same genetic code that’s used in your cells (and the cells of all living creatures). Also, like cell-based life, viruses have genetic variation and can evolve.

Detailed explanation-2: -Like other viruses, animal viruses are tiny packages of protein and nucleic acid. They have a protein shell, or capsid, and genetic material made of DNA or RNA that’s tucked inside the caspid. They may also feature an envelope, a sphere of membrane made of lipid. Animal virus capsids come in many shapes.

Detailed explanation-3: -Viral genomes consist of DNA or RNA only, never both. DNA and RNA molecules can be double stranded or single stranded, linear or circular (Fig. 1.6), segmented (composed of multiple pieces of nucleic acid) or nonsegmented.

Detailed explanation-4: -Nucleic Acid-Just as in cells, the nucleic acid of each virus encodes the genetic information for the synthesis of all proteins. While the double-stranded DNA is responsible for this in prokaryotic and eukaryotic cells, only a few groups of viruses use DNA.

Detailed explanation-5: -Viruses contain nucleic acid as RNA or DNA. These molecules possess all the genetic information of the virus.