What are the characteristics of viruses?

1) non-cellular life forms
2) genetic material (DNA or RNA) is surrounded by a protein shell
3) parasites, do not have their own metabolism (can only function in host cells)

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.