The student is expected to: 4C compare the structures of viruses to cells, describe viral reproduction, and describe the role of viruses in causing diseases such as human immunodeficiency virus (HIV) and influenza

KEY CONCEPT Infections can be caused in several ways.

Viruses, bacteria, viroids, and prions can all cause infection. Any disease-causing agent is called a pathogen. 1 nanometer (nm) = one billionth of a meter 100 nm eukaryotics cells 10,000-100,000 nm viroids 5-150 nm viruses 50-200 nm prokaryotics cells 200-10,000 nm prion 2-10 nm

A virus is made of DNA or RNA and a protein coat. non-living pathogen can infect many organisms A viroid is made only of single-stranded RNA. causes disease in plants passed through seeds or pollen

A prion is made only of proteins. causes misfolding of other proteins results in diseases of the brain