Viruses

Virus cells need a host to reproduce. The virus attaches to the host cell and injects the DNA or RNA.The DNA or RNA then incorporates itself into the host cell to reproduce its parts.Once the parts are all made and assembled the viruses typically lyses the cell to go and infect other cells.

Viruses

Virus Structure-Smaller (20-400nm)-Acellular-No cell wall or membrane-No ribosomes-DNA or RNA is enclosed in a proteint coat.-Vaccines and antivirals used for treatment.

Vs. Bacteria Cell Structure-Larger (1000nm)-DNA and RNA floating freely in cytoplasm. -Has cell wall and cell membrane.-Has ribosomes-Antibiotics used for treatment.

The Flu Virus (top)The Ebola Virus (bottom)

Are they living?

Reproduction

VACCINES ARE IMPORTANT!!They protect you from highly contagious diseases that are airborne like measles. For a population to have immunity against a disease, 80% of the population must get vaccines. This is called herd immunity.

Vaccines

It is debated, but most scienctist agree that viruses are non-living. Scientist think this, because viruses lack most of the characteristics of living things. For example, they are acellular, they do not have energy metabolism, and they cannot reproduce without a host cell.