Viruses

Viruses are an acellular microorganism, which means they have no cell and therefore are considered to be non-living by most. They contain either RNA or DNA (never both) but require the organelles of a host cell to reproduce. Common examples include the flu, common cold, measles, herpes, Ebola, and AIDS.
== Structure ==
=== Nucleic Acid Core ===
Contains either DNA or RNA, and either single-stranded or double-stranded.
=== Protein Coat ===
Also called a capsid, the protein coat is made up of capsomeres, which come in two different shapes: rods and triangles.
Together, the nucleic acid core and protein coat form a nucleocapsid.
=== Other ===
Some viruses have envelopes, which are made of lipids, proteins, and carbohydrates, and some have spikes.
== Shapes ==
=== Helical ===
Tube-like capsid formed from rod capsomers. Examples include rabies, measles and flu.
=== Polygon ===
Made up of triangular capsomers, can often end up with a 20-sided polygon. Examples include AIDS and herpes viruses.
=== Complex ===
Made of a mix of rods and triangles, often infect bacteria, and are known as bacteriophages. (spider-looking thing)
== Size ==
Their size range from 20 to 450 nm, which means that they are filterable (pass through just like how water is filterable) through 200nm filter paper. Most filters will therefore not sterilize.
== Classification ==
# Nucleic acid: RNA/DNA
# Nucleic acid: Single/double
# Envelop
# Shape/Size