The use of pesticides and herbicides is carefully monitored because of the effect they can have on the environment. Which of the following is a possible negative effect of the use of these chemicals on the environment?
a
b
OO
Runoff carries these chemicals into lakes and streams
These chemicals are expensive to produce
Storage space for these chemicals is limited
These chemicals cannot be purchased in large bulk
C С
c
d

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).