If someone's biologic parents are both schizophrenic, he or she has a greater than 90% chance of being schizophrenic

Andrew's friends have noticed that lately he sleeps constantly but is always tired and complains of feeling too hot or too cold. Although Andrew had formerly been very athletic, lately his muscle tone has been greatly reduced

The source of Andrew's problem is probably an ______ gland. a. overactive pituitary b. underactive pituitary c. overactive thyroid d. underactive thyroid

Variance in an experiment may be due to:

a. chance. b. the independent variable. c. a confound. d. all of these