Mad cow disease appeared first in Great Britain around 1990 causing the deaths of over 400 cattle per week. (Experts believe this disease was already present in British cattle by the 1960s.) This disease was discovered in Canadian beef around 2003. Evidently, putting meat remains back into cattle food is a very dangerous practice. This disease can attack humans.

Prions are a tpe of primitive virus like creatures that contains proteins, but lack any nucleic acids. Mad cow disease is caused by a prion.

e have lumped all the virus like lifeforms herein, as science is still working on the taxonomy tree in this area.

Viruses are the most primitive of lifeforms. These organisms are usually too small to be seen by typical microscopes. Viruses are composed of a acid nucleus and some proteins. These organisms need to invade a living cell of a host in order to grow and reproduce. Several well known diseases are caused by viruses including Hepatitis, HIV, Mumps, Influenze, Rabies, and Yellow Fever.

There are several even more primitive virus like creatures that include viroids and prions. (Viroids can cause some plant health issues, and Prions can cause the mad cow disease.)

NEW SEARCH