Final answer:
The polio virus is conferred chemical stability and resistance by its protective protein coat, specifically a na_ked icosahedral capsid composed of capsomeres, which provides more resistance than viruses with phospholipid envelopes.
Step-by-step explanation:
Chemical stability and resistance in the polio virus is conferred by its capsid. The polio virus exhibits a na_ked icosahedral capsid structure, lacking an outer phospholipid envelope. This makes the virus more resistant to environmental challenges such as changes in temperature, pH levels, and certain disinfectants compared to enveloped viruses like influenza, HIV, or measles. These non-enveloped viruses shield their nucleic acid with a sturdy protective protein coat, composed of multiple protein subunits called capsomeres. These capsomeres interlock to form the closely packed capsid, which not only protects the nucleic acid but also contributes to the infectivity and stability of the virus.