What is the function of chordae tendinae? A. hold valve shut when ventricles contract
B. open valve to allow blood from atrium to flow into ventricles

Which describes the effect of prolonged stress on blood pressure? it causes blood pressure to decrease. it has little or no effect on blood pressure. it causes the heart to pump with more force. it causes blood pressure to increase.

Is it ok to have a tooth growing on my crotch and this is school related

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.