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