What statement is true of prions?
a) prions are produced by viruses.
b) prion diseases can be prevented by cooking your meat.
c) prions are abnormally shaped proteins that cause spongiform encephalopathies.
d) there are no prion diseases of humans, although there are several examples in animals.

Prions are abnormally shaped proteins that cause spongiform encephalopathies. (Ans C)

Explanation:

Prions : Prions are proteinaceous infectious particle or misfolded proteins with the ability to transmit their misfolded shape into normal shape protein.  They are also responsible for some neurodegenerative diseases in mammals. They can affect both animals as well as humans.

Prion disease occurs when normal prion protein (present on the surface of many cells) becomes clump (abnormal) in the brain. This accumulation of abnormal protein in the brain can cause disease.

Spongiform encephalopathies also called prion disease. Spongiform encephalopathies affect the nervous system and brain of animals & humans. It is caused by a degeneration of brain tissues giving it a spongy appearance.