Asimple experiment showed the action spectrum for photosynthesis. a green
alga on a microscope slide received light that had been separated into its colors
by a prism. the dots in the graph represent the molecules that accumulated
when the different wavelengths of light were absorbed by the green alga.
high
s
light absorption
es
green alga
400
450
650
700
500 550 600
wavelength (nm)
green-yellow
violet-blue
orange-red
what are these molecules likely to be

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).