| what is a virus? | A virus is a nonliving particle made up of nucleic acid and a protein coat |
| characteristics of virus? | 1-virusus range in size from small (poliovirus 20nm)to large smallpox virus 250nm.
3- They must enter a living cell and use the host cell’s ribosomes, ATP, enzymes, and other molecules to reproduce.
5-The shape nucleic acid may be helical, a closed loop, or long strand (depending on virus) |
| write down how viruses are grouped ? | based on whether they have RNA or DNA or based on nucleic acid is single stranded or double stranded or based on their shape and structure. |
| what are viroids? | are the smallest known particles that are able to replicate. A viroid is made up of a short, single strand of RNA that does not have a capsid. |
| what are prions? | are abnormal forms of protein that clump together inside cells and cause cell death. |
