Exercise increases the delivery of blood, oxygen and nutrients to the brain, muscles and vital organs due to A. increased endorphins

B. decreased circulation

C. increased circulation

D. Increased serotonin levels

Which of the following statemens is not true about the consequences of alcohol?

International social workers work on global level and play a key role in improving quality of life for

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.