In the 1880s, Louis Pasteur developed a method of weakening viruses. The weakened viruses could be injected into healthy individuals. How is this method effective in fighting viral diseases? O The immune system develops antibodies in response to the weakened viruses. O The rate of genetic mutation in the host is decreased due to the introduction of weakened viruses. O Weakened viruses are unable to enter the host organism. O The weakened viruses attach to unaffected viruses in the host and interrupt the viral reproductive cycle.

Which of the following statements apply to bacteria but not to virus O Contain genetic material in the form of DNA or RNA O Can be infected by bacteriophages O All apply O Have genes that can be counted by the fingers on one hand

which of the following is NOT a mechanism by which viruses can damage the human body (ie- harm us)? causes our viral infections may lead to the release of too much cytokines/chemical signals O may cause our defenses/immune system to over-react Othey produce and release toxins O may cause cancer Otheir replication (life cycle) destroys our cells

Explain why the COVID-19 virus has been described as being sporadic, then epidemic and now pandemic. – look up the definitions of sporadic, epidemic and pandemic and relate them to COVID-19