Over the past 20 years, the efforts of the united states have decreased the amount of pollutants in the environment.

Khurshid is recovering from a heart attack. which type of rehabilitative care would she benefit from the most?

Which of the following supports the argument that viruses are nonliving? a) they are not cellular.b) their dna does not encode proteins.c) they have rna rather than dna.d) they do not evolve.

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.