Astudent is conducting an experiment to determine what type of soil earthworms prefer, wet or dry. ten earthworms are released into a cardboard box that contains dry soil on one side and wet soil on the other. over 24 hours, the student records the number of earthworms on both sides every hour. what component of the above experiment is the dependent variable? a) soil moisture b) number of trials c) average number of earthworms in each type of soil d) species of worm used

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).