Viruses

Viruses A cellular

No organelles

Parasitic

Must infect a host in order to reproduce

Infect a diversity of organisms Examples: AIDS, chicken pox,

herpes

Do not have all characteristics of life Can’t metabolize or grow

Evolutionary pathway unclear

Morphology Viron: single virus particle

Basic structure: Nucleic acid core (DNA or RNA) Capsid: Protein external covering

4 main shapes Filaments Isometric Envelope Head and Tail

Genetic Information Can be DNA or RNA genome

Genome is small

DNA viruses: DNA directs host cell’s replication Make new copies of viral genome and then transcribe

and translate the viral proteins

RNA viruses: RNA makes enzymes that can replicate RNA into DNA

Ways a virus can spread

1. Contact transmission Shaking hands, kissing Bodily fluids (saliva, breast milk)

2. Indirect contact Utensils, cups, bedding

3. Droplet spread Coughing, sneezing

If a virus spreads quickly it can become an epidemic

Virus Prevention Vaccine

Builds immunity Prepared from live or dead virus

Human childhood vaccines: polio, mumps, measles, rubella, chicken pox

Live vaccines more effective Small chance it could mutate to

become infectious

Today’s Lab Virus transmission simulation

Complete as a class Pretend to share bodily fluids

Dolphin case study: Based on real life Significant increase in dolphin

strandings in 2013–2014

Possibly due to cetacean morbillivirus To complete the lab

Complete internet research Answer the questions in the word

document