Questions: Question 2 Prions are strands of nucleic acids encased in a protein coat. viral nucleic acids integrated into the host chromosomes. viral-infected cells. infectious proteins with no associated nucleic acid. proteins coded by genes.

The answer is the fourth one: infectious proteins with no associated nucleic acid.

Explanation for each option:

1. Strands of nucleic acids encased in a protein coat: This describes viruses, not prions. Viruses have nucleic acids (either DNA or RNA) surrounded by a protein coat.

2. Viral nucleic acids integrated into the host chromosomes: This refers to a provirus or prophage, which is a stage in the life cycle of some viruses, not prions.

3. Viral-infected cells: This describes cells that have been infected by viruses, not prions.

4. Infectious proteins with no associated nucleic acid: This is the correct description of prions. Prions are misfolded proteins that can induce other normal proteins to also misfold, leading to disease.

5. Proteins coded by genes: While prions are proteins, they are not directly coded by genes in the way typical proteins are. They are infectious agents that propagate by transmitting their misfolded protein state.

In summary, prions are infectious proteins with no associated nucleic acid.