What do semilunar valves separate? ventricle and artery
atrium and artery
atrium and ventricle
ventricle and vein

In a study of a weight loss program, 40 subjects lost a mean of 3.0 lb after 12 months. does the weight loss program have practical significance? a. yes, because the weight loss program worked and the subjects lost a mean of 3.0 lb. b. no, because the mean weight loss of 3.0 lb after one year does not seem to justify the program. c. no, because the sample of 40 subjects was too small to determine if the program was useful. d. yes, because the mean weight loss of 3.0 lb after one year does seems to justify the program.

Dr. leung has been studying consistent trends in how males and females have selected their mates throughout the long history of humankind. dr. dauphine is most likely a(n) psychologist.

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.