The physical expression of a genetic code is called a(n) __________

Research evidence indicates that two biological factors are most likely to influence a

person's sexual orientation. These are a. postnatal hormonal exposure and differences in brain structure. b. prenatal exposure to androgens and differences in genital development. c. differences in brain and genital development. d. prenatal hormonal exposure and heredity. e. heredity and brain development.

Professor Kim's students designed an experiment to

investigate whether self-esteem was affected by how often she called on them when they raised their hand in class. They planned to count the number of times each student was called on when they raised their hand, ask each student how their self-esteem was before and after the experiment, and compare their responses based on how often they were called upon. Their causal hypothesis was, "If the professor calls on you more often when you raise your hand, your self-esteem will go up." What is one significant flaw in their design? a) They have no independent variable. b) They have no operational definition for self-esteem. c) They have no dependent variable. d) They don't have a sample.