Which statement about anorexia nervosa and bulimia nervosa is true?
a. approximately half of those with anorexia nervosa go on to develop bulimia nervosa, indicating that the two disorders may not be distinct but may represent phases of the same eating disorder.
b. the binge eating/purging type of bulimia nervosa is different from anorexia nervosa in that it involves both low weight and amenorrhea.

Choose the incorrect statement (a) the motor end plate membrane is only capable of generating graded potentials, but it is contiguous with the skeletal muscle sarcolemma, which can generate action potentials. (b) propagation of an action potential through the t-tubules into the sarcoplasmic reticulum triggers the release of ca++ into the cytoplasm of a skeletal muscle fiber. (c) the generation of suprathreshold endplate potentials in multiple muscle fibers could be due to the increased frequency of action potential generation at the axon hillock of a single motor neuron. (d) a greater amount of ach would be found in the presynaptic vesicles of a motor unit that fired several action potentials after exposure to botulinum toxin, than in a motor unit that fired several action potentials after exposure to the venom of the krait snake (which contains α-bungarotoxin).