If there is a difference between actual conditions and set points, which part of a feedback mechanism sends a message to either increase or decrease the activity of particular effectors? a. sensor b. stimulus c. response d. integrating center

Which of the following statements best describes an opportunistic infection (ol)? a. ols are common only to people with healthy immune systems b. ols are more frequent in the earlier stages of hiv c. ols are the common cause of death of people with hiv/aids d. ols can be deadly to perfectly healthy people.