diversity of virus structure Flashcards
What does the diversity in virus structure suggest about their origins?
The diversity in virus structure suggests that viruses have multiple evolutionary origins, as no genes are found in all viruses.
What types of genetic material can viruses have?
Viruses can have DNA or RNA as their genetic material, and it can be single or double-stranded, with circular or linear configurations.
How do single-stranded RNA viruses replicate?
Single-stranded RNA viruses use one of three methods:
- Positive-sense RNA: directly used as mRNA.
- Negative-sense RNA: transcribed to make mRNA.
- Retroviruses: create a double-stranded DNA copy of RNA, then transcribe the negative-sense strand into mRNA.
What is the difference between enveloped and non-enveloped viruses?
Enveloped viruses have a membrane derived from the host cell’s phospholipids, with viral glycoproteins. They are common in animal viruses.
Non-enveloped viruses (like most bacteria and plant viruses) do not have a lipid membrane.
How do viruses typically leave the host cell?
Viruses burst the host cell (lysis) to be released into the environment.
What role does the membrane play in enveloped viruses?
The membrane of an enveloped virus helps it make contact with and infect host cells by using viral glycoproteins.
