The viruses responsible for causing polio and hydrophobia are
How many strains of viruses are responsible for causing common cold in man?
Which of the following disease is not caused by viruses ?
(a) measles (b) smallpox (c) cholera (d) polio
Viruses are neither living nor dead organisms. However, they are responsible for a large number of diseases occurring in human beings. Which of the following diseases is not caused by a virus?