NEET BIOLOGY

Detailed explanation-1: -Not only are prions not alive (and contain no DNA), they can survive being boiled, being treated with disinfectants, and can still infect other brains years after they were transferred to a scalpel or other tool.

Detailed explanation-2: -Prions and viruses are not regarded as living things because they fall short of a few key requirements for life. For instance, viruses and prions do not contain cells and do not have an energy metabolism system. They lack any cell organelles, hence they are unable to carry out any type of metabolic activity.

Detailed explanation-3: -Prions are virus-like organisms made up of a prion protein. These elongated fibrils (green) are believed to be aggregations of the protein that makes up the infectious prion. Prions attack nerve cells producing neurodegenerative brain disease. “Mad cow” symptoms include glazed eyes and uncontrollable body tremor.

Detailed explanation-4: -Prion diseases are transmissible, untreatable, and fatal brain diseases of mammals. Their cause is highly unusual: The host’s normal prion protein can, for unknown reasons, malfunction and assemble into structured aggregates called prions that cause infectious brain disease.