Which of the following best explains why multiple exercises are needed to improve muscular strength and endurance throughout the body? a. push-ups don't exercise leg muscle groups. b. different exercises are needed to improve different muscle groups. c. weight lifting is more important for muscle strength than endurance. d. not all muscle groups can be exercised simultaneously.

Brad was almost hit by a speeding truck as he crossed the street. his heart began to race, and he felt extremely afraid as he jumped out of the way in just enough time to avoid the truck. a psychologist who supports the theory of emotion would claim that based on the arousal brad experienced, he appraised the situation and then labeled his racing heart as fear. a. james-lange b. cannon-bard c. schachter two-factor d. evolutionary

There is only one copy machine at your office. you have to make 1000 copies of an expense report. after you begin copying, two other employees show up in the copy room. each has to make only 10 copies each. what is the proper etiquette in this situation?

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.