A member of a gene pair that can control the appearance of a certain trait only if it is paired with another, similar type gene is a ______ gene

In the Netherlands, where there are guidelines for physician-assisted suicide and euthanasia, a study found that

a. assisted suicide is approached cautiously and used sparingly. b. passive euthanasia was requested much more often than active euthanasia. c. active euthanasia was hardly requested at all. d. assisted suicide accounted for most of the medically-assisted deaths.

Joe repetitively taps his pencil on his desk before a test in order to relieve tension. Which type of habit behavior is Joe engaging in?

a. vocal tic b. negative habit c. motor tic d. nervous habit