What is the single effective most effective way to prevent infections? What are two additional ways to control the spread of germs that are spread through the air, such as colds? (Site 1)

Viruses use the host's machinery to make copies of themselves. however, some human viruses require a type of replication that humans do not normally have. for example, humans normally do not have the ability to convert rna into dna. how can these types of viruses infect humans, when human cells cannot perform a particular role that the virus requires? a) the virus causes mutations in the human cells, resulting in the formation of new enzymes that are capable of performing these roles.b) the viral genome codes for specialized enzymes not in the host.c) the virus infects only those cells and species that can perform all the replication roles necessary.d) viruses can stay in a quiescent state until the host cell evolves this ability.

Which of the following human diseases is caused by a virus that requires reverse transcriptase to transcribe its genome inside the host cell? a) herpesb) aidsc) smallpoxd) influenza

Mary is 14 year old her resting heart rate is 70 beats per minute. calculate 50% of mary's maximum heart rate to fine her target heart rate